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Title: AN EXAMINATION OF RELATIVE AGE EFFECTS AMONG JUNIOR ELITE WRESTLERS.
Creator: Kelly, Jayla, Fukuda, David, University of Central Florida
Abstract / Description: The purpose of this examination was to evaluate relative age effects among junior elite wrestlers across gender, weight class, and competitive rule sets. Using biographical data, this thesis explores trends representing an oversampling of athletes born earlier in the year, accompanied by potential effects for success in sport and an impact on retention rates. Currently, the use of chronological age is the most common form of classifying sports participants, though this type of classification...
Show moreThe purpose of this examination was to evaluate relative age effects among junior elite wrestlers across gender, weight class, and competitive rule sets. Using biographical data, this thesis explores trends representing an oversampling of athletes born earlier in the year, accompanied by potential effects for success in sport and an impact on retention rates. Currently, the use of chronological age is the most common form of classifying sports participants, though this type of classification may have potentially negative long- and short-term implications. Thus, the results may provide an evaluation of weight categorization as a less discriminatory competitive format in junior elite wrestlers.
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Date Issued: 2015
Identifier: CFH0004804, ucf:45487
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFH0004804

Title: Role of brain derived neurotrophic factor (BDNF) in stimulating strength improvements induced by short-term resistance training.
Creator: Church, David, Hoffman, Jay, Stout, Jeffrey, Fukuda, David, Stock, Matt, University of Central Florida
Abstract / Description: Strength adaptations from short-term resistance training are thought to be related primarily to neurological adaptations. Considering brain-derived neurotrophic factor (BDNF) role in the nervous system, it is possible that BDNF has a role in these adaptations. Fourteen untrained males were randomized into either a resistance training (RT; n =8) or control (CON; n=6) group. Motor unit (MU) recruitment at 50% and 80% of each participant's maximal voluntary isometric contraction (MVIC), muscle...
Show moreStrength adaptations from short-term resistance training are thought to be related primarily to neurological adaptations. Considering brain-derived neurotrophic factor (BDNF) role in the nervous system, it is possible that BDNF has a role in these adaptations. Fourteen untrained males were randomized into either a resistance training (RT; n =8) or control (CON; n=6) group. Motor unit (MU) recruitment at 50% and 80% of each participant's maximal voluntary isometric contraction (MVIC), muscle cross sectional area (CSA) and thickness (MT), as well as one-repetition maximum (1RM) of the squat (SQT), leg press (LP), and leg extension (LE) were performed before (PRE) and after (POST) the training period. Following the MU assessment, the recruitment threshold (RT; % MVIC) and mean firing rate (MFR; pulse per second [pps]) of each MU were determined. Linear regression was used to quantify the slope (pps/% MVIC) and y-intercept (pps) of the MFR versus RT relationship for each participant and time point. Participants completed an acute resistance exercise bout at PRE and POST consisting of 3 sets of 8 (-) 10 repetitions with 90 seconds of rest between each set of SQT, LP, and LE. Blood samples were obtained following a 4-hour fast before (BL), immediately-(IP), and one-(1H) hour post resistance exercise. RT subjects performed the same resistance exercise protocol at PRE twice a week for 3-weeks. CON subjects were instructed to not perform any resistance exercise. Area under the curve (AUC) analysis was determined by the trapezoidal method. Pearson product-moment correlations were used to examine selected bivariate relationships. The ?BDNF AUC was significantly correlated to the relative 80% ?y-intercept (r=-0.626, p=0.030), and trended to be correlated to the relative 80% ?slope (r=0.551, p=0.063). Our results indicate that ? in plasma BDNF concentrations appear to be related to ?'s MU recruitment at high intensities (80% of MVIC) of exercise.
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Date Issued: 2018
Identifier: CFE0006988, ucf:51665
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006988

Title: SHORT TERM EXAMINATION OF PHYSICAL ACTIVITY AND SLEEP QUALITY WITH CHILDREN WITH AUTISM SPECTRUM DISORDER.
Creator: Barnes, Demani Barak, Garcia, Jeanette M., Fukuda, David H., University of Central Florida
Abstract / Description: Children diagnosed with Autism Spectrum Disorder (ASD) may not be meeting the recommended amounts of physical activity (PA) or obtain a sufficient amount of sleep, however, few studies have objectively compared PA, sedentary behavior, and sleep quality between typically developing (TD) youth, and youth with ASD. Therefore, the purpose of this study was to compare levels of PA, sedentary behavior, and sleep quality between youth with ASD and TD youth. Twenty-three children with ASD and 12 TD...
Show moreChildren diagnosed with Autism Spectrum Disorder (ASD) may not be meeting the recommended amounts of physical activity (PA) or obtain a sufficient amount of sleep, however, few studies have objectively compared PA, sedentary behavior, and sleep quality between typically developing (TD) youth, and youth with ASD. Therefore, the purpose of this study was to compare levels of PA, sedentary behavior, and sleep quality between youth with ASD and TD youth. Twenty-three children with ASD and 12 TD children wore the Actigraph GT9X accelerometer over seven days and nights to assess activity and sleep. Youth with ASD had significantly greater levels of sedentary behavior (p=.02), and had less sleep efficiency compared to TD youth (p=.0001). Additionally, TD youth were more likely to achieve the recommended levels of PA compared to youth with ASD (p=.003). Results suggest that youth with ASD have poorer health habits compared to TD youth. Interventions should be developed to target health behaviors in youth with ASD.
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Date Issued: 2019
Identifier: CFH2000490, ucf:45830
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFH2000490

Title: EFFECTS OF A MODIFIED JUDO PROGRAM ON PSYCHOSOCIAL FACTORS IN TYPICALLY DEVELOPING AND CHILDREN WITH AUTISM SPECTRUM DISORDER: A MIXED-METHODS STUDY.
Creator: Tomey, Keanu L., Garcia, Jeanette M., Fukuda, David H., University of Central Florida
Abstract / Description: PURPOSE: The purpose of this study was to examine the effect of a modified judo training program on psychosocial health in both typically developing (TD) and children with Autism Spectrum Disorder (ASD) using a mixed-methods approach. METHODS: The sample consisted of 5 children with ASD and 5 TD children (age=8-11yrs) who participated in 10 sessions of a modified judo program during their typical physical education time for school. Psychosocial factors (enjoyment, perceived competence,...
Show morePURPOSE: The purpose of this study was to examine the effect of a modified judo training program on psychosocial health in both typically developing (TD) and children with Autism Spectrum Disorder (ASD) using a mixed-methods approach. METHODS: The sample consisted of 5 children with ASD and 5 TD children (age=8-11yrs) who participated in 10 sessions of a modified judo program during their typical physical education time for school. Psychosocial factors (enjoyment, perceived competence, benefits of PA) were assessed at baseline and post intervention, with completion of all measures dependent upon the level of comfort expressed by the participant. At the end of the program, children took part in focus group discussions centered around their experience with the program, while key school staff participated in semi-structured interviews based on their observations of the program. All focus group discussions and interviews were audio-recorded and transcribed verbatim. RESULTS: Quantitative results for pre and post psychosocial measures showed no significant differences existed between PA self-efficacy (p=.99), PA enjoyment (p=.6), and barriers to PA (p=.27). Qualitative results revealed that the majority of the participants found the program to be enjoyable, with partner centered activities being particularly fun. Suggestions for improvement included increasing the duration and frequency of the judo classes. All children reported a desire to continue participating in the judo classes. Findings from staff interviews indicated that school staff observed improvements in psychosocial health and behavior both immediately following a judo class, and throughout the intervention period. Increased self-confidence was mentioned by all participating school staff members. CONCLUSION: Despite the lack of significant quantitative findings, psychosocial benefits were observed in both TD children and children with ASD, with all participants reporting their desire to continue with the program. Future studies should examine the psychosocial benefits in a judo-training program in larger sample of children over longer durations.
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Date Issued: 2017
Identifier: CFH2000252, ucf:46017
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFH2000252

Title: THE EFFECTS OF AN 8-WEEK JUDO PROGRAM ON THE PSYCHOSOCIAL FACTORS OF CHILDREN DIAGNOSED WITH AUTISM SPECTRUM DISORDER.
Creator: Burrell, Auckland J, Garcia, Jeanette M., Fukuda, David H., University of Central Florida
Abstract / Description: The purpose of this study was to analyze the effects of an 8-week judo program on self-competency, physical activity (PA) motivation, and enjoyment of PA in children diagnosed with Autism Spectrum Disorder (ASD). METHODS: The sample included 20 children (ages 8 – 17) with a primary diagnosis of ASD. The participants completed an 8-week judo program that occurred once a week for 45 minutes. Participants were instructed to complete a series of questionnaires that measured athletic self...
Show moreThe purpose of this study was to analyze the effects of an 8-week judo program on self-competency, physical activity (PA) motivation, and enjoyment of PA in children diagnosed with Autism Spectrum Disorder (ASD). METHODS: The sample included 20 children (ages 8 – 17) with a primary diagnosis of ASD. The participants completed an 8-week judo program that occurred once a week for 45 minutes. Participants were instructed to complete a series of questionnaires that measured athletic self-competency, PA motivation, and PA enjoyment at baseline and at the end of the 8-week judo program. Paired t-tests were conducted to examine differences in psychosocial factors from baseline and post-judo. Additionally, correlational analyses were conducted to examine the association between the psychosocial variables and attendance during the 8-week program. RESULTS: Although increases in psychosocial factors were observed following the cessation of the judo program, these changes were not statistically significant for any of the psychosocial factors following the 8-week program. There was a significant, positive association between PA motivation and judo attendance (r=.43, p=.05), however, neither athletic competency nor PA enjoyment were correlated with judo attendance. CONCLUSION: Although not significant, improvement in psychosocial factors were observed post-judo program. Future studies should consider increasing the duration and frequency of the judo program to potentially elicit greater changes in psychosocial factors related to PA.
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Date Issued: 2019
Identifier: CFH2000577, ucf:45614
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFH2000577

Title: Noninvasive myographical assessments following unaccustomed resistance exercise.
Creator: Boone, Carleigh, Fragala, Maren, Hoffman, Jay, Stout, Jeffrey, Fukuda, David, University of Central Florida
Abstract / Description: Traditionally, post-exercise muscular alterations have been examined using invasive techniques that lack the ability to single out individual muscle groups. Sonomyography, tensiomyography, and electrical impedance myography allow for noninvasive skeletal muscle assessment. This project aimed to examine changes in muscle contractility and composition that occur in the early stages of recovery following unaccustomed exercise. METHODS: Twenty-one untrained adults (21.9 (&)#177; 1.9 y) performed...
Show moreTraditionally, post-exercise muscular alterations have been examined using invasive techniques that lack the ability to single out individual muscle groups. Sonomyography, tensiomyography, and electrical impedance myography allow for noninvasive skeletal muscle assessment. This project aimed to examine changes in muscle contractility and composition that occur in the early stages of recovery following unaccustomed exercise. METHODS: Twenty-one untrained adults (21.9 (&)#177; 1.9 y) performed exercise (-) 10 (&)#215; 10 maximal eccentric knee extensions (-) with their nondominant leg. For each repetition, participants moved through 90(&)deg; range of motion at 90(&)deg;•s-1 with a passive return to the start position. Each set was separated by 60 seconds of rest. Sonomyography, tensiomyography, electrical impedance myography, and maximal isometric contractions of the knee extensors (RF (&) VL) of both legs were performed before (BL), immediately after (IP), and 24 hours post-exercise (24H). RESULTS: Peak torque and rate of torque development were unaltered in response to the eccentric protocol. Significant limb (&)#215; time interactions were noted for reactance, phase angle, and delay time of the exercised VL, and echo intensity of the exercised RF. Compared to the dominant leg, the nondominant leg displayed significantly greater changes (p (<) 0.05) in VL delay time and RF echo intensity at IP. Following exercise, bilateral alterations were identified for reactance, phase angle, maximal displacement, delay time, contraction velocity, cross-sectional area, and thickness of the RF, as well as resistance, echo intensity, cross-sectional area, and thickness of the VL. No between-sex differences were noted in response to exercise. CONCLUSIONS: In the absence of performance decrements, sonomyography, tensiomyography, and electrical impedance myography successfully detected acute changes in skeletal muscle composition and function following an acute bout of eccentric exercise in untrained men and women. While the exercised leg exhibited specific responses in delay time and echo intensity, bilateral changes are theorized to have occurred due to contralateral stabilization of the non-exercised leg. The current results suggest that different muscle actions (i.e., eccentric and isometric) promote similar consequences to muscle strength, size, echogenicity, contractility, and bioelectrical properties.
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Date Issued: 2019
Identifier: CFE0007432, ucf:52731
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007432

Title: Acute Effects of Placebo and Open-Label Placebo Treatments on Muscle Strength, Voluntary Activation, and Neuromuscular Fatigue.
Creator: Swafford, Alina, Stout, Jeffrey, Fukuda, David, University of Central Florida
Abstract / Description: Placebo treatments have long been used to study the psychological effects of expectancy and conditioning on an inert intervention. Interestingly, open-label placebo treatments (i.e., directly telling subjects they are receiving an inactive intervention) have recently shown promise in minimizing pain in clinical patient populations. We utilized a repeated measures design to examine the acute effects of placebo, open-label placebo, and control treatments on muscle strength and voluntary...
Show morePlacebo treatments have long been used to study the psychological effects of expectancy and conditioning on an inert intervention. Interestingly, open-label placebo treatments (i.e., directly telling subjects they are receiving an inactive intervention) have recently shown promise in minimizing pain in clinical patient populations. We utilized a repeated measures design to examine the acute effects of placebo, open-label placebo, and control treatments on muscle strength and voluntary activation (Experiment #1), as well as neuromuscular fatigue (Experiment #2). Twenty-one untrained males (n=11) and females (n=10) visited the laboratory on three occasions to receive each treatment in a randomized, counter-balanced manner. All visits involved a pretest, 15-minute intervention period, and posttest. In Experiment #1, knee extensor maximal voluntary isometric contraction (MVIC) peak torque and percent voluntary activation were evaluated. In Experiment #2, subjects performed 20, six-second MVICs while surface electromyographic signals were detected from the vastus lateralis. Subjective assessments of energy and perceived exertion were also examined. In Experiment #1, no differences among interventions were demonstrated for peak torque or voluntary activation, but a main effect revealed that energy levels increased following each treatment (p = .016, ?2 = .257). Experiment #2 demonstrated that placebo and open-label placebo treatments had no influence on neuromuscular fatigue, but there were main effects for declines in absolute (p = .001, ?2 = .675) and normalized peak torque (p = .001, ?2 = .765), electromyographic mean frequency (p = .001, ?2 = .565), neuromuscular efficiency (p = .001, ?2 = .585), and energy levels (p = .006, ?2 = .317). Collectively, placebo and open-label placebo treatments had minimal influence on strength, voluntary activation, and fatigue resistance in untrained subjects. We speculate that our subject population and study design intricacies that are unique to placebo trials may explain our findings.
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Date Issued: 2018
Identifier: CFE0007254, ucf:52204
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007254

Title: Minimal Effects of Moderate Normobaric Hypoxia on the Upper-Body Work-Time Relationship in Recreationally-Active Women.
Creator: Starling-Smith, Tristan, Fukuda, David, Stout, Jeffrey, Wells, Adam, University of Central Florida
Abstract / Description: INTRODUCTION: Hypoxic training protocols vary with respect to exercise modality and intensity. Variables derived from the work-time relationship, namely critical power (CP) and anaerobic working capacity (W'), have been previously examined during upper and lower-body exercise in hypoxia. However, these studies have neglected to examine women who reportedly exhibit different responses to exercise in hypoxia compared to men.PURPOSE: To evaluate the effects of moderate normobaric hypoxia on the...
Show moreINTRODUCTION: Hypoxic training protocols vary with respect to exercise modality and intensity. Variables derived from the work-time relationship, namely critical power (CP) and anaerobic working capacity (W'), have been previously examined during upper and lower-body exercise in hypoxia. However, these studies have neglected to examine women who reportedly exhibit different responses to exercise in hypoxia compared to men.PURPOSE: To evaluate the effects of moderate normobaric hypoxia on the parameters of the work-time relationship during upper body exercise in women. METHODS: Thirteen recreationally active women (age: 22.7 (&)#177; 2.6 y; height: 167 (&)#177; 8.6 cm; weight: 66.4 (&)#177; 9.7 kg; body fat: 27.6 (&)#177; 5% body fat) completed a graded exercise test in both normobaric hypoxia (H; FiO2=~14%) and normoxia (N; FiO2=~20%) to exhaustion on an arm ergometer to determine V?O2peak and peak power output (PPO). Each participant completed four constant work-rate arm-cranking tests at 90-120% PPO in both environmental conditions. Linear regression was used to estimate CP and AWC via the work-time relationship during the constant work-rate tests. Paired samples t tests compared mean differences between V?O2peak, PPO, CP and AWC between conditions (N vs. H). Two-way (condition (&)#215; intensity) repeated measures ANOVA was used to compare total work and time-to-exhaustion.RESULTS: H significantly reduced VO2peak (N: 1.73L/min (&)#177; .31L/min vs. H: 1.62L/min (&)#177; .27L/min, p=.008) but had minimal effects on PPO (N: 78.08W(&)#177;14.51W vs. H: 75.38W(&)#177;13.46, p=.089), CP (N: 57.44W(&)#177;18.89W vs. H: 56.01W(&)#177;12.36W, p=.546), and AWC (N: 4.81kJ(&)#177;1.01kJ vs. H: 4.56kJ(&)#177;.91kJ, p=.510). No significant condition (&)#215; intensity interactions were noted for total work or time-to-exhaustion (p(>).05). CONCLUSIONS: Moderate normobaric hypoxia significantly reduced VO2peak but had minimal effects on CP and AWC using the work-time model
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Date Issued: 2018
Identifier: CFE0007248, ucf:52184
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007248

Title: CHANGES IN RUNNING AND MULTIPLE OBJECT TRACKING PERFORMANCE DURING A 90-MINUTE INTERMITTENT SOCCER PERFORMANCE TEST (iSPT). A PILOT STUDY.
Creator: Girts, Ryan, Wells, Adam, Stout, Jeffrey, Fukuda, David, Hoffman, Jay, University of Central Florida
Abstract / Description: Multiple object tracking (MOT) is a cognitive process that involves the active processing of dynamic visual information. In athletes, MOT speed is critical for maintaining spatial awareness of teammates, opponents, and the ball while moving at high velocities during a match. Understanding how MOT speed changes throughout the course of a competitive game may enhance strategies for maintaining optimal player performance. The objective of this study was to examine changes in MOT speed and...
Show moreMultiple object tracking (MOT) is a cognitive process that involves the active processing of dynamic visual information. In athletes, MOT speed is critical for maintaining spatial awareness of teammates, opponents, and the ball while moving at high velocities during a match. Understanding how MOT speed changes throughout the course of a competitive game may enhance strategies for maintaining optimal player performance. The objective of this study was to examine changes in MOT speed and running performance during a 90-minute intermittent soccer performance test (iSPT). A secondary purpose was to examine the relationship between aerobic capacity and changes in MOT speed.Seven competitive female soccer players age: 20.4 (&)#177; 1.8 y, height: 166.7 (&)#177; 3.2 cm, weight: 62.4 (&)#177; 4.0 kg, VO2max: 45.8 (&)#177; 4.6 ml/kg/min-1) completed an intermittent soccer performance test (iSPT) on a Curve(TM) non-motorized treadmill (cNMT). The iSPT was divided into two 45-minute halves with a 15-minute halftime [HT] interval, and consisted of six individualized velocity zones. Velocity zones were consistent with previous time motion analyses of competitive soccer matches and based upon individual peak sprint speeds (PSS) as follows: standing (0% PSS, 17.8% of iSPT), walking (20% PSS, 36.4% of iSPT), jogging (35% PSS, 24.0% of iSPT), running (50% PSS, 11.6% of iSPT), fast running (60% PSS, 3.6% of iSPT), and sprinting (80% PSS, 6.7% of iSPT). Stand, walk, jog and run zones were combined to create a low-speed zone (LS). Fast run and sprint zones were combined to create a high-speed zone (HS). MOT speed was assessed at baseline (0 min.) and three times during each half of the iSPT. Dependent t-tests and Pearson correlation coefficients were utilized to analyze the data. Across 15-minute time blocks, significant decreases in distance covered and average speed were noted for jogging, sprinting, low-speed running, high-speed running, and total distance (p's (<) 0.05). Players covered significantly less total distance during the second half compared to the first (p = 0.025). Additionally, significant decreases in distance covered and average speed were observed during the second half for the sprint and HS zones (p's ? 0.008). No significant main effect was noted for MOT speed across 15-minute time blocks. A trend towards a decrease in MOT speed was observed between halves (p = 0.056). A significant correlation was observed between the change in MOT speed and VO2max (r = 0.888, p = 0.007). The fatigue associated with 90 minutes of soccer specific running negatively influenced running performance during the second half. However, increased aerobic capacity appears to be associated with an attenuation of cognitive decline during 90-minutes of soccer specific running. Results of this study indicate the importance of aerobic capacity on maintaining spatial awareness during a match.
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Date Issued: 2018
Identifier: CFE0007183, ucf:52290
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007183

Title: The effects of dynamic versus isometric postactivation potentiation on collegiate female rowers.
Creator: Harat, Idan, Fukuda, David, Stout, Jeffrey, Wells, Adam, University of Central Florida
Abstract / Description: Post-activation potentiation (PAP) has been shown to improve acute power-based performance, and the potential to enhance rowing performance. To examine PAP effects with rowing performance, 40 collegiate female rowers performed isometric potentiating (ISO), dynamic potentiating (DYN) and typical control (CON) warm-up protocols, after which they completed a three-minute all-out test (3MT) to evaluate their total distance, peak power, mean power, critical power, anaerobic working capacity (W')...
Show morePost-activation potentiation (PAP) has been shown to improve acute power-based performance, and the potential to enhance rowing performance. To examine PAP effects with rowing performance, 40 collegiate female rowers performed isometric potentiating (ISO), dynamic potentiating (DYN) and typical control (CON) warm-up protocols, after which they completed a three-minute all-out test (3MT) to evaluate their total distance, peak power, mean power, critical power, anaerobic working capacity (W') and stroke rate. Fifteen-second splits for distance and mean power were also analyzed. The PAP protocols were performed on a rowing ergometer, in a movement pattern that simulated rowing. ISO consisted of 5 (&)#215; 5-second static muscle actions with the ergometer handle rendered immovable with a nylon boat-strap, while DYN consisted of 2 (&)#215; 10-second all-out rowing bouts, separated by a 2-minute rest interval. A two-way (condition by experience level) interaction was found for distance, mean power and W' with significant differences (DYN (>) CON; 5.6 m, 5.9W and 1561.6 J) for more experienced rowers ((>)3.75 years; n=19) and no differences for less experienced rowers (n=18). A main effect for stroke rate was found with DYN(>)CON (1 s/min). Split analysis of mean power output revealed a two-way (condition by 15s split) interaction independent from experience level. Mean power in DYN was significantly greater than CON and ISO in the 15-30, 30-45, 45-60 and 60-75 second intervals. These results suggest that dynamic PAP may be beneficial for experienced rowers and that these strategies might benefit a greater power output over shorter distances regardless of experience. Future studies should investigate potential benefits of this protocol over a full race distance and identify the difference between experienced and less experienced rowers.
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Date Issued: 2019
Identifier: CFE0007465, ucf:52665
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007465

Title: Effects of Rest Position on Ultrasound-Derived Morphological Characteristics of the Vastus Lateralis and Lower-Body Force Production.
Creator: Varanoske, Alyssa, Wells, Adam, Fukuda, David, Stout, Jeffrey, Mangine, Gerald, University of Central Florida
Abstract / Description: INTRODUCTION: Ultrasound assessment of the lower body typically encompasses 10-15 minutes of supine rest prior to examination because of the potential influence of gravitational fluid shifts on tissue size and composition. However, examination of the vastus lateralis (VL) muscle requires individuals to lay in the lateral recumbent position, and this change in position may influence muscle morphological characteristics and their ability to predict muscle function.PURPOSE: The purpose of this...
Show moreINTRODUCTION: Ultrasound assessment of the lower body typically encompasses 10-15 minutes of supine rest prior to examination because of the potential influence of gravitational fluid shifts on tissue size and composition. However, examination of the vastus lateralis (VL) muscle requires individuals to lay in the lateral recumbent position, and this change in position may influence muscle morphological characteristics and their ability to predict muscle function.PURPOSE: The purpose of this investigation was to examine the effect of rest position on ultrasound-derived morphological characteristics of the VL and to determine whether or not rest position affects the relationships between muscle morphological characteristics of the VL and lower-body force and power production. METHODS: Thirty-one resistance-trained males (age: 23.0 (&)#177; 2.1 years; height: 1.79 (&)#177; 0.08 m; body mass: 87.4 (&)#177; 11.7 kg) participated in this investigation. Muscle morphological characteristics, including cross-sectional area (CSA), muscle thickness (MT), pennation angle (PA), echo intensity (UnCorEI), subcutaneous adipose tissue thickness (SFT), and EI corrected for SFT (CorEI) of the VL were assessed in the dominant limb after 15 minutes of rest in 3 recumbent positions: supine (SUP), dominant lateral recumbent (DLR), non-dominant lateral recumbent (NDLR), as well as after 15 minutes of standing (ST) and immediately after laying down (IP). Following ultrasound assessments, participants completed unilateral performance assessments, including vertical jumps (UVJ), isometric/isokinetic testing, and a 1-repetition maximum (1-RM) leg press. RESULTS: A repeated-measures analysis of variance revealed significantly different (p (<) 0.05) CSA, MT, PA, UnCorEI, and SFT in ST compared to recumbent positions after 15 minutes of rest (NDLR, DLR, and SUP). Additionally, significant differences were observed between recumbent positions for CSA, CorEI, and UnCorEI; however, no differences were observed for MT, PA, and SFT. Different magnitudes of relationships were observed between muscle morphological characteristics measured after rest in different positions and performance variables. However, muscle morphology after IP generally appears to be the best predictor of performance for most variables, although utilizing the NDLR and DLR positions may provide comparable, or potentially stronger results for variables such as IsokPF. The relationship between muscle morphology and various performance variables in ST were weaker compared to the recumbent positions examined, specifically for IsokPF, 1-RM leg press, and for all UVJ variables, except total work.CONCLUSIONS: Muscle morphology differs depending on the rest position utilized prior to ultrasound analysis. These rest positions also affect the ability for muscle morphology to predict lower-body force production. Future research should consider evaluation of muscle morphology of the VL after IP in the prediction of muscle function; however, NDLR and DLR may also be used. SUP and ST provide significantly weaker relationships for some performance variables compared to the other recumbent positions.
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Date Issued: 2019
Identifier: CFE0007550, ucf:52610
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007550

Title: Ultrasound Measured Flexor Muscle Thickness in the Forearms of Rock Climbers.
Creator: Marsala, Michael, Garcia, Jeanette, Fukuda, David, Stock, Matt, University of Central Florida
Abstract / Description: PURPOSE: To examine differences in the forearms of rock climbers using ultrasound to measure the muscle thickness of the finger flexors. METHODS: A total of 33 participants were recruited, 22 climbers (22.23 years; 68% male) and 11 controls (21.8; 55% male). Climbers provided self-reported ratings of their climbing ability, skill level, and preferred mode of climbing (e.g. sport climbing vs. bouldering). Anthropometric measures, including body fat percentage, were measured in all participants...
Show morePURPOSE: To examine differences in the forearms of rock climbers using ultrasound to measure the muscle thickness of the finger flexors. METHODS: A total of 33 participants were recruited, 22 climbers (22.23 years; 68% male) and 11 controls (21.8; 55% male). Climbers provided self-reported ratings of their climbing ability, skill level, and preferred mode of climbing (e.g. sport climbing vs. bouldering). Anthropometric measures, including body fat percentage, were measured in all participants. Ultrasound measurements were taken with the participant lying on their back on a padded table with their dominant hand supinated. Muscle thickness measurements were taken at the forearm where a peak of the forearm flexors was identified on the medial aspect of the forearm after a circumference measurement and small mark was made. The distance from the ulna and radius to the muscle-skin interface was measured, as well as echo intensity surrounding the median nerve using a third party program. RESULTS: Approximately 50% of climbers rated themselves as (")intermediate("), and the other 50% rated themselves as (")advanced(") climbers, while 77% of the 22 climbers classified themselves as primarily (")sport climbers("), and 23% classified themselves as (")boulderers("). Body fat percentages were significantly different at 19.14(&)#177;6.99 and 30.02(&)#177;7.6 for climbers and controls. Ulnar and radial muscle thickness values were significantly higher in climbers, 4.23(&)#177;.39and 2.32(&)#177;.39, respectively, and 3.61(&)#177;.6 and 1.84(&)#177;.31 in controls (p(<).001). No differences in echo intensity were observed between climbers and non-climbers. DISCUSSION: The findings suggests that there are differences in flexor muscle thickness observed in earlier stages of rock climbing. Echo intensity of the flexor muscles were also measured, however significant variance in results warrants further investigation. Future studies should consider larger samples to better determine differences among muscle thickness and echo intensity across climbing abilities and mode of climbing, thus allowing for more specific training programs to be developed at each phase of training.
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Date Issued: 2019
Identifier: CFE0007677, ucf:52473
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007677

Title: Examining Work-To-Rest Ratios To Optimize Upper Body Sprint Interval Training.
Creator: Lamonica, Michael, Fukuda, David, Hoffman, Jay, Stout, Jeffrey, Fragala, Maren, University of Central Florida
Abstract / Description: The primary purpose of this study was to compare the metabolic influence of varying work-to-rest ratios during upper body sprint interval training (SIT). Forty-two recreationally trained men were randomized into one of three training groups [10s work bouts with two minutes of rest (10:2, n = 11) or four minutes of rest (10:4, n = 11), or 30s work bouts with four minutes of rest (30:4, n = 10)] or a control group (CON, n = 10). Participants underwent six training sessions over two weeks with...
Show moreThe primary purpose of this study was to compare the metabolic influence of varying work-to-rest ratios during upper body sprint interval training (SIT). Forty-two recreationally trained men were randomized into one of three training groups [10s work bouts with two minutes of rest (10:2, n = 11) or four minutes of rest (10:4, n = 11), or 30s work bouts with four minutes of rest (30:4, n = 10)] or a control group (CON, n = 10). Participants underwent six training sessions over two weeks with four to six 'all-out' sprints. During pre- and post-intervention visits, participants underwent a graded exercise test to determine maximal oxygen consumption (V?O2peak) and peak power output (PPO), four constant-work rate trials to determine critical power (CP), anaerobic working capacity (W'), and electromyographic fatigue threshold (EMGFT), and an upper body Wingate test to determine peak power (PP), mean power (MP), and total work (TW). Oxygen consumption and blood lactate during the Wingate test generated estimates of oxidative, glycolytic, and ATP-PCr energy system provisions. An analysis of covariance was performed on all testing measurements collected at post with the associated pre-values used as covariates. V?O2peak was greater in 30:4 (p = .007) and 10:2 (p = .036) compared to CON and PPO was greater in 30:4 than CON (p = .007). No differences were observed between groups in CP (p = .530), W' (p = .900), EMGFT (p = .692), PP (p = .692), MP (p = .290), or TW (p = .291). Relative energy contribution (p = .026) and energy expenditure (p = .019) of the ATP-PCr energy system was greater in 10:4 compared to CON. SIT protocols with larger work-to-rest ratios induce enhanced aerobic adaptions, whereas smaller work-to-rest ratios may enhance ATP-PCr utilization in the upper body over a short-term two-week intervention.
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Date Issued: 2018
Identifier: CFE0007036, ucf:51978
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007036

Title: The Impact of Judo on Aggressive Behaviors in Youth with Autism Spectrum Disorder.
Creator: Rivera, Paola, Garcia, Jeanette, Fukuda, David, Stout, Jeffrey, University of Central Florida
Abstract / Description: The aim of this study was to examine the effects of an 8-week judo program on lifestyle habits and behavior in children with Autism Spectrum Disorder (ASD). METHODS: Participants included 25 children (ages 8-17), with a formal diagnosis of ASD. The sample participated in an 8-week judo program (45 minutes, 1x week), with measures taken at baseline and at the end of the 8-weeks. In order to assess activity levels and sleep quality, participants were instructed to wear Actigraph GT9X...
Show moreThe aim of this study was to examine the effects of an 8-week judo program on lifestyle habits and behavior in children with Autism Spectrum Disorder (ASD). METHODS: Participants included 25 children (ages 8-17), with a formal diagnosis of ASD. The sample participated in an 8-week judo program (45 minutes, 1x week), with measures taken at baseline and at the end of the 8-weeks. In order to assess activity levels and sleep quality, participants were instructed to wear Actigraph GT9X Accelerometers for 7 days and nights. In order to assess behavioral changes, parents were given the ABC survey to fill out at baseline and post-intervention. Non-parametric paired t-tests were conducted to compare differences in behaviors, MVPA, SB, and sleep quality (i.e. sleep efficiency, total sleep time, number of awakenings, and wake after sleep onset) pre and post judo. RESULTS: Results indicated there was a strong negative correlation (r= -0.632) with inappropriate behaviors and the number of classes attended. Participants also spent a significantly greater percentage of time in daily MVPA (8% vs 4%, p=0.05) following the program. There was a significant increase in total minutes of sleep duration (572.56 vs 333.8, p=0.008) following the program, and although not statistically significant, a trend existed for improved sleep efficiency (92% vs 88%, p=0.1). CONCLUSION: Despite no significant differences in ABC scores pre and post-judo, a strong association between class attendance and lower ABC scores were observed, along with improvements in MVPA and sleep quality. Future studies should include larger samples of youth with ASD, over a longer intervention period.
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Date Issued: 2019
Identifier: CFE0007525, ucf:52591
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007525

Title: The Effects of a 10-week Judo Program on Cortisol and Stress in Children with Autism Spectrum Disorder.
Creator: Renziehausen, Justine, Garcia, Jeanette, Fukuda, David, Stout, Jeffrey, University of Central Florida
Abstract / Description: Children diagnosed with Autism Spectrum Disorder (ASD) often have increased levels of stress, leading to dysregulated production of cortisol. Elevated levels of cortisol have numerous known adverse health consequences, and therefore, interventions should be established to help attenuate cortisol production. As judo combines physical activity and mindfulness practice, it may aid in stress reduction and decreased levels of cortisol. Purpose: To examine the effects of a 10-week judo program on...
Show moreChildren diagnosed with Autism Spectrum Disorder (ASD) often have increased levels of stress, leading to dysregulated production of cortisol. Elevated levels of cortisol have numerous known adverse health consequences, and therefore, interventions should be established to help attenuate cortisol production. As judo combines physical activity and mindfulness practice, it may aid in stress reduction and decreased levels of cortisol. Purpose: To examine the effects of a 10-week judo program on stress reactions and salivary cortisol levels in youth with ASD. Methods: 20 children with ASD participated in the 10-week judo program. Changes in acute (before and after one judo session) and chronic salivary cortisol levels were assessed at baseline and post intervention. Parents of participants were asked to complete the Stress Survey Schedule (SSS) to determine severity of stress reactions. The SSS consists of 10 subscales: changes, anticipation, unpleasant, positives, food related, rituals, social/environmental, sensory/personal, fears, and life stressors. Sleep quality was assessed via Actigraph GT9X accelerometers over a 7-day period at baseline and post-intervention. Paired samples t-tests were used to determine differences SSS pre/post-intervention. Repeated measures ANOVA was conducted to determine differences and in cortisol levels before and after one judo session and pre and post-intervention. Spearman correlations were used to determine correlations between sleep quality and subscales of the SSS. Results: Although not statistically significant, a trend was noted indicating a decrease in cortisol levels following one judo session (p=.057). Nonsignificant reductions in the subscales (")changes (p=.14)(") and (")unpleasant (p=.12)(") of the SSS were also observed. Conclusion: Acute changes in cortisol levels may be seen following one session of judo. Subscales of parent-reported questionnaire may also show improvements following 10 weeks of participation in a judo program.
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Date Issued: 2019
Identifier: CFE0007522, ucf:52622
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0007522

Title: Evaluation of Echogenicity Within and Between Ultrasonographic Images of the Vastus Lateralis.
Creator: Varanoske, Alyssa, Fukuda, David, Stout, Jeffrey, Hoffman, Jay, University of Central Florida
Abstract / Description: PURPOSE: The purpose of this study was to examine the echo intensity (EI) values of different ultrasound (US) images of the vastus lateralis (VL) using panoramic imaging in the transverse plane (PTI) and still imaging in the longitudinal plane (SLI). Secondary purposes of this study were to examine VL homogeneity and to determine relationships between subcutaneous adipose tissue thickness (SubQ) adjacent to the muscle and EI. METHODS: Twenty-four recreationally-trained collegiate males (20.2 ...
Show morePURPOSE: The purpose of this study was to examine the echo intensity (EI) values of different ultrasound (US) images of the vastus lateralis (VL) using panoramic imaging in the transverse plane (PTI) and still imaging in the longitudinal plane (SLI). Secondary purposes of this study were to examine VL homogeneity and to determine relationships between subcutaneous adipose tissue thickness (SubQ) adjacent to the muscle and EI. METHODS: Twenty-four recreationally-trained collegiate males (20.2 (&)#177; 1.6 years; height: 178.1 (&)#177; 6.6 cm; weight: 82.2 (&)#177; 13.4 kg) participated in this investigation. EI, cross-sectional area (CSA), muscle thickness (MT), and SubQ of the VL were assessed in the dominant limb (DOM) via three PTI and SLI. The best PTI was divided into three compartments of equal horizontal length (tertiles) to examine EI homogeneity. RESULTS: A repeated-measures ANOVA revealed a significant main effect for image/tertile between measures of EI (p (<) 0.001). The EI of PTI (57.976 (&)#177; 8.806 AU) was significantly lower than EI of SLI (65.453 (&)#177; 11.023 AU) (p = 0.002), however significant positive correlations existed between the two (r = 0.681; p (<) 0.001). Additionally, the EI of the SLI was significantly greater than the EI of the lateral tertile (58.717 (&)#177; 9.877 AU) (p = 0.001) and the EI of the posterior tertile (56.354 (&)#177; 9.887 AU) (p = 0.002). Although there was no significant difference between EI of the SLI and EI of the anterior tertile (59.065 (&)#177; 9.126 AU), a trend towards a significant difference was shown (p = 0.051). No significant differences in EI values between tertiles were identified. Significant differences in MT existed between PTI and SLI (PTI: 2.178 (&)#177; 0.367 cm; SLI: 2.015 (&)#177; 0.397 cm; p = 0.003), however MT values from PTI and SLI were significantly positively correlated with one another (r = 0.809, p (<) 0.001). Significant differences in SubQ existed between PTI and SLI (PTI: 0.217 (&)#177; 0.167 cm; SLI: 0.316 (&)#177; 0.225 cm; p (<) 0.001), however SubQ values from PTI and SLI were significantly positively correlated with one another (r = 0.915, p (<) 0.001). No relationship between EI and SubQ from either image was found (PTI and SubQ: r = -0.067, p = 0.754; SLI and SubQ: r = -0.114, p = 0.597). SLI yielded slightly lower standard errors of measurement (SEM) and coefficients of variation (CV), indicating better precision compared to PTI. CONCLUSIONS: EI of the VL appears to be homogeneous as assessed in a PTI in recreationally-trained collegiate males. Additionally, PTI and SLI yield different EI, CSA, MT, and SubQ values, but these values are highly correlated. The use of SLI requires less time, equipment, and technical expertise, and therefore may be advantageous for use in future studies.
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Date Issued: 2016
Identifier: CFE0006193, ucf:51117
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006193

Title: Effects of an Acute High-Volume Isokinetic Intervention on Inflammatory and Strength Changes: Influence of Age.
Creator: Gordon, Joseph, Hoffman, Jay, Stout, Jeffrey, Fukuda, David, University of Central Florida
Abstract / Description: PURPOSE: The purpose of this study was to compare the effects of a high volume isokinetic intervention on lower body strength and inflammation, as well as markers of muscle damage in the subsequent 48 hours between younger and middle-aged men. METHODS: 19 healthy, recreationally trained men were randomly assigned to two groups, younger adults (YA: 21.8 (&)#177; 2.0 y; 90.7 (&)#177; 11.6 kg; 21.5 (&)#177; 4.1 % body fat), or middle-aged adults (MA: 47.0 (&)#177; 4.4 y; 96.0 (&)#177; 21.5; 24.8...
Show morePURPOSE: The purpose of this study was to compare the effects of a high volume isokinetic intervention on lower body strength and inflammation, as well as markers of muscle damage in the subsequent 48 hours between younger and middle-aged men. METHODS: 19 healthy, recreationally trained men were randomly assigned to two groups, younger adults (YA: 21.8 (&)#177; 2.0 y; 90.7 (&)#177; 11.6 kg; 21.5 (&)#177; 4.1 % body fat), or middle-aged adults (MA: 47.0 (&)#177; 4.4 y; 96.0 (&)#177; 21.5; 24.8 (&)#177; 6.3 % body fat). Both groups reported to the human performance laboratory (HPL) on four separate occasions. On the first visit (D1), anthropometric assessment, as well as a familiarization session with the isokinetic dynamometer, was performed. A muscle damaging protocol (HVP) was performed on the second visit (D2) consisting of 8 sets of 10 repetitions at 60(&)deg;(&)#183;sec-1 on the isokinetic dynamometer. An assessment protocol (AP) was performed to assess performance decrements between the YA and MA groups. For this protocol, a maximal voluntary isometric contraction (MVIC) was performed, as well as 3 isokinetic kicks at 2 different speeds (240(&)deg;(&)#183;sec-1 and 60(&)deg;(&)#183;sec-1). For the MVIC, values for peak torque (PKT), average torque (AVGT), rate of torque development at 100 ms (RTD100), and 200 ms (RTD200) were recorded. For the isokinetic kicks at 240(&)deg;(&)#183;sec-1 (ISK240) and 60(&)deg;(&)#183;sec-1 (ISK60), values were also recorded for peak torque (PKT), average torque (AVGT), as well as peak power (PP), and average power (AVGP). The AP was performed before the HVP (BL), immediately after the HVP (IP), 120 minutes after the HVP (120P), as well as one (24H) and two (48H) days following the HVP. Blood draws were also taken at BL, IP, 24H, and 48H, as well as 30 minutes (30P), and 60 minutes (60P) following the HVP to assess circulating levels of creatine kinase (CK), myoglobin (Mb), c-reactive protein (CRP), and interleukin 6 (IL-6). Ultrasound assessment was also performed at BL and IP as well to assess changes in muscle morphology as a result of the intervention. Performance, blood, and ultrasound markers were analyzed using a repeated measures ANOVA to observe between group comparisons for all of the outcome variables. RESULTS: There were no group differences observed for isometric or isokinetic peak torque or average torque, nor were there differences in isokinetic peak power or average power between the two groups as a result of the intervention. There were, however, differences in the pattern for rate of torque development at 100 ms and 200 ms between the two groups. RTD 100 was decreased at IP and 48H in YA, with MA showing decreases at IP, but also 120P and 24H unlike YA. RTD200 was decreased at all time points in YA, while MA was decreased at IP, 24H, and 48H, but not 120P. For markers of muscle damage and inflammation, there were no differences in the response of Mb, CK, CRP, or IL-6 between groups. CONCLUSIONS: Age does not appear to be a driving factor in the inflammatory or muscle damage response from a high volume isokinetic intervention. Though changes in peak torque and average torque from a high volume isokinetic intervention do not seem to differ between younger and middle-aged adults, the rate of torque production at 100ms and 200ms is different between groups. This suggests that while recovery to average or maximal strength after an exercise bout may not be affected greatly by age, the rate of neuromuscular recovery from exercise may be primarily affected by other factors such as training status.
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Date Issued: 2017
Identifier: CFE0006594, ucf:51259
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006594

Title: Effects of a 10-Week Introductory Judo Course on Postural Control During Reactionary Bilateral Gripping Task With Varied Stances and Lower Body Power Performance.
Creator: Muddle, Tyler, Fukuda, David, Hoffman, Jay, Stout, Jeffrey, University of Central Florida
Abstract / Description: PURPOSE: The purpose of the present study is twofold: 1.) Examine the effects of 10-weeks of an introductory judo course on postural control during maximal bilateral isometric handgrip testing using different stance conditions and lower body power performance, and 2.) To analyze the relationship between maximal bilateral handgrip exertions on postural control during varied stance conditions. METHODS: Twenty recreationally active men and women divided into two an experimental group, (JDO) (n =...
Show morePURPOSE: The purpose of the present study is twofold: 1.) Examine the effects of 10-weeks of an introductory judo course on postural control during maximal bilateral isometric handgrip testing using different stance conditions and lower body power performance, and 2.) To analyze the relationship between maximal bilateral handgrip exertions on postural control during varied stance conditions. METHODS: Twenty recreationally active men and women divided into two an experimental group, (JDO) (n = 10; 21.70 (&)#177; 3.83 y; 169.91 (&)#177; 6.01 cm; 73.89 (&)#177; 12.10 kg; 19.01 (&)#177; 8.06% BF), and a control group, (CON) (n = 10; 21.50 (&)#177; 2.84 y; 170.06 (&)#177; 8.28 cm; 76.62 (&)#177; 12.03 kg; 22.41 (&)#177; 6.64% BF), participated in this study. Both groups completed pre-testing, performing nine randomly assigned experimental trials measuring center of pressure (COP) variables during the performance of a bilateral reactionary gripping task using varied stance conditions. Each trial consisted of bilateral maximal voluntary contractions (MVC) measured simultaneously with a handgrip dynamometer, three times with a neutral (N), dominant foot forward (D), and non-dominant (ND) foot forward stance. Furthermore, participants performed three bilateral countermovement jumps (CMJ) trials. All trials were completed while standing on a portable force platform, which was used, in conjunction with corresponding software, to track COP amplitude in the mediolateral (COPML) and anteroposterior (COPAP) directions, COP mean velocity (MV), and COP area (AREA) while gripping the dynamometer, and ground reaction forces, peak force (CMJPKF), peak power (CMJPP), and rate of power development (CMJRPD), during CMJ performance. Subjects were instructed to grasp the dynamometers as forcefully as possible for ?5-sec during each trial. All trials were separated by a recovery period of 60-sec. A Waterloo Handedness and Footedness Questionnaire was used to determine subject upper and lower body laterality. Participants repeated the testing protocol following the conclusion of the 10-week course. RESULTS: No significant interactions were observed in MVC strength of the DOM and NON hands during any of the three stance conditions following the 10-week judo course. Furthermore, no significant interactions were observed for any of the COP variables. However, a significant main effect of stance was observed for COPML, MV, and AREA. Results did reveal that CMJPP significantly improved in the JDO group (PRE: 3584.70 (&)#177; 716.59W - POST: 3750.10 (&)#177; 699.61W) following the 10-week judo course, while no change was observed in the CON group (PRE: 3693.10 (&)#177; 1083.77W (-) POST: 3654.40 (&)#177; 1023.94W). However, no change was seen in CMJPKF or CMJRPD. CONCLUSIONS: The results of this investigation indicate that 10-weeks of an introductory judo course may increase CMJPP, however, has no effect on postural control or bilateral MVC strength of the DOM and NON hand during varied stance conditions. Furthermore, results reveal that bilateral MVC exertion has no influence on postural control performed during varied stance conditions.
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Date Issued: 2016
Identifier: CFE0006148, ucf:51157
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006148

Title: The Reproducibility and Validity of Using the Dmax Method to Predict Physical Working Capacity at Fatigue Threshold.
Creator: Riffe, Joshua, Stout, Jeffrey, Hoffman, Jay, Fukuda, David, University of Central Florida
Abstract / Description: Although the original (ORG) physical working capacity at fatigue threshold (PWCFT) assessment has demonstrated strong reliability and sensitivity to training and/or nutritional interventions, limitations may exist regarding the method of PWCFT estimation. However, a relatively new mathematical method, called Dmax, has been shown to be objective and reliable when estimating metabolic and neuromuscular fatigue thresholds. To date, however, no study has examined whether the Dmax method for...
Show moreAlthough the original (ORG) physical working capacity at fatigue threshold (PWCFT) assessment has demonstrated strong reliability and sensitivity to training and/or nutritional interventions, limitations may exist regarding the method of PWCFT estimation. However, a relatively new mathematical method, called Dmax, has been shown to be objective and reliable when estimating metabolic and neuromuscular fatigue thresholds. To date, however, no study has examined whether the Dmax method for estimating the work rate at PWCFT is similar to the ORG method. PURPOSE: The purpose of this study is to evaluate the reliability and validity of the Dmax-EMG method for estimating and tracking changes in PWCFT. METHODS: In the reproducibility study, 11 men (age: 21.9 (&)#177; 1.37 years; height: 175.6 (&)#177; 8.65 cm; body mass: 82.1 (&)#177; 13.92 kg) completed two incremental exercise tests (GXT) to exhaustion on nonconsecutive days. In the validity study, 11 active men (age: 23.4 (&)#177; 3.0 years; height: 177.9 (&)#177; 7.8 cm; body mass: 80.9 (&)#177; 10.7 kg) and 10 active women (age: 22.3 (&)#177; 3.1 years; height: 166.6 (&)#177; 9.5 cm; body mass: 62.8 (&)#177; 8.7 kg) volunteered to perform 12 sessions of high-intensity interval training (HIIT) over 4-weeks along with a pre- and post-training GXT to compare the Dmax to the ORG method of estimating PWCFT. RESULTS: The reproducibility study revealed no significant differences between the first (181.5 (&)#177; 29.2 W) and second (181.9 (&)#177; 26.18 W) GXT trials (p = 0.87). In addition, ICC3,1 resulted in 0.949 with an SEM of 6.28 W and a MD of 17.41 W. In the cross-validation, the CE between actual and predicted PWCFT was not statistically different at pre (-6.7 W; p (>) 0.05) or post (-7.2 W; p (>) 0.05). Pre (r = 0.87) and post (r = 0.84) validity coefficients were considered very strong and the pre and post TE PWCFT values were 30.8 W and 32.5 W, respectively. Wide limits of agreement were calculated in the Bland-Altman analyses (pre: -68.36 to 54.93 W; post: -57.77 to 72.06 W) with no significant biases in both pre (-6.7 (&)#177; 30.8 W; p = 0.330) and post (-7.2 (&)#177; 32.5 W; p = 0.325). In addition, 95.2% and 100% participants fell within (&)#177;1.96 standard deviations of the mean difference for pre and post, respectively. CONCLUSION: Results of the study suggest that the Dmax method is both a reproducible and a valid method to estimate PWCFT when compared to the ORG method in young men.
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Date Issued: 2016
Identifier: CFE0006168, ucf:51155
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006168

Title: The effects of four weeks of high intensity interval training and (&)#223;-hydroxy-(&)#223;-methylbutyric free acid on the onset of neuromuscular fatigue.
Creator: Miramonti, Amelia, Stout, Jeffrey, Hoffman, Jay, Fukuda, David, University of Central Florida
Abstract / Description: This study investigated the effects of high intensity interval training (HIIT) and ?-hydroxy-?-methylbutyric free acid (HMBFA) on the onset of neuromuscular fatigue in healthy young men and women. Thirty-seven subjects (22 men and 15 women; mean (&)#177; SD age = 22.8 (&)#177; 3.4yrs) completed an incremental cycle ergometer test (GXT) to exhaustion. During the GXT, electromyography (EMG) signals from the right vastus lateralis were recorded to determine the power output at the onset of...
Show moreThis study investigated the effects of high intensity interval training (HIIT) and ?-hydroxy-?-methylbutyric free acid (HMBFA) on the onset of neuromuscular fatigue in healthy young men and women. Thirty-seven subjects (22 men and 15 women; mean (&)#177; SD age = 22.8 (&)#177; 3.4yrs) completed an incremental cycle ergometer test (GXT) to exhaustion. During the GXT, electromyography (EMG) signals from the right vastus lateralis were recorded to determine the power output at the onset of neuromuscular fatigue (PWCFT), and peak wattage was used to assign individual training loads.After baseline testing (PRE), subjects were randomly assigned to one of three groups: control (C, n = 9), training with placebo (P, n = 14), or training with supplementation (S, n = 14). Subjects assigned to P and S completed 12 HIIT sessions over 4 weeks while subjects assigned to C were asked to maintain their normal diet and activity patterns. After 4 weeks, subjects returned for post-testing (POST). The PWCFT values (W) were determined using a DMAX method. The EMG amplitude root mean square ((&)#181;Vrms) values were used to generate a third-order polynomial regression (3PR) representing the increase in (&)#181;Vrms versus time of the GXT. The onset of fatigue (TF) was defined as the x-value (time, s) of the point on the 3PR that measured the maximal perpendicular distance from the line between the first and last data points. TF was used to estimate PWCFT according to the equation: PWCFT = PO + a ? (n/N), where PO is the power output of the stage in which TF occurred, a is the increment in power output between GXT stages (25W), n is the difference (s) between TF and the beginning of the stage during which TF occurred, and N is the duration of a stage (120s).A two-way repeated measures ANOVA was used to identify group (&)#215; time interaction for PWCFT. If a significant interaction occurred, one-way factorial ANOVAs were used. Fisher's least significant difference post hoc comparisons were performed between groups. If a significant main effect occurred, dependent samples t-tests with Bonferroni corrections (p = [0.05/3] = 0.017) were performed across time for each group.The two-way ANOVA resulted in a significant interaction (F = 6.69, p = 0.004). Follow-up analysis with one-way ANOVA resulted in no difference among groups at PRE (F = 0.87, p = 0.43), however a significant difference was shown for POST values (F = 5.46, p = 0.009). Post-hoc analysis among POST values showed significant differences between S and both P (p = 0.034) and C (p = 0.003). No differences (p = 0.226) were noted between P and C. Paired samples t-tests detected significant changes following HIIT for S (p (<) 0.001) and P (p = 0.016), but no change in C (p = 0.473).Results of this study indicate that HIIT was effective in delaying the onset of fatigue, but supplementation with HMBFA in conjunction with HIIT was more effective than HIIT alone. An increase in PWCFT represents an increase in the maximal power output an individual can sustain without eliciting fatigue. Therefore, HIIT can be used to improve performance in both endurance activities as well as intermittent sports. In addition, HMBFA supplementation is a simple method that can be used to maximize the benefits of HIIT.Acknowledgments: Metabolic Technologies, Inc. provided the supplement and funding for this study.
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Date Issued: 2015
Identifier: CFE0006043, ucf:50968
Format: Document (PDF)
PURL: http://purl.flvc.org/ucf/fd/CFE0006043

Electromyography (4)	+ -
Inflammation (4)	+ -
Resistance Training (3)	+ -
Autism Spectrum Disorder (2)	+ -
Critical Power (2)	+ -

Muscle Damage (2)	+ -
fatigue threshold (2)	+ -
knee extensors (2)	+ -
neuromuscular fatigue (2)	+ -
physical activity (2)	+ -
repeated sprint ability (2)	+ -
running performance (2)	+ -
soccer (2)	+ -
ultrasound (2)	+ -
3-min all-out run (1)	+ -
5000m running (1)	+ -
5k running (1)	+ -
?-Hydroxy-?-Methylbutyrate (1)	+ -
Active Video Games (1)	+ -
Adhesion (1)	+ -
Aerobic (1)	+ -
Aging (1)	+ -
Altitude (1)	+ -
Autism (1)	+ -
BDNF (1)	+ -
C-C Chemokine Receptor 2 (1)	+ -
CD11b (1)	+ -
Center of pressure (1)	+ -
Chemokines (1)	+ -
Chemotaxis (1)	+ -

ETD Collection (36)	+ -
Honors Collection (4)	+ -

University of Central Florida (40)	+ -
Fukuda, David (37)	+ -
Stout, Jeffrey (34)	+ -
Hoffman, Jay (24)	+ -
Fragala, Maren (9)	+ -

Wells, Adam (7)	+ -
Garcia, Jeanette (6)	+ -
Fisher, Thomas (3)	+ -
Fukuda, David H. (3)	+ -
Garcia, Jeanette M. (3)	+ -
Stock, Matt (3)	+ -
Baker, Kayla (2)	+ -
Beyer, Kyle (2)	+ -
Boone, Carleigh (2)	+ -
Lamonica, Michael (2)	+ -
Mangine, Gerald (2)	+ -
Varanoske, Alyssa (2)	+ -
Arroyo Delgado, Eliott (1)	+ -
Barnes, Demani Barak (1)	+ -
Bohner, Jonathan (1)	+ -
Burrell, Auckland J (1)	+ -
Church, David (1)	+ -
Dawson, Nicole (1)	+ -
Ferguson, Matthew (1)	+ -
Girts, Ryan (1)	+ -
Gonzalez, Adam (1)	+ -
Gordon, Joseph (1)	+ -
Harat, Idan (1)	+ -
Hoffman, Mattan (1)	+ -
Jajtner, Adam (1)	+ -

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