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- Title
- The Effects of 6-weeks of Resistance Training on the Neuromuscular Fatigue Threshold in Older Adults.
- Creator
-
Emerson, Nadia, Stout, Jeffrey, Hoffman, Jay, Fragala, Maren, University of Central Florida
- Abstract / Description
-
Age-related deficits in muscle mass, strength, and function place an increased burden of work on existing skeletal muscle and may lead to early onset of neuromuscular fatigue (NMF) during activities of daily living. Resistance exercise (RE) is the proven method for improving neuromuscular function in healthy older adults. PURPOSE: To investigate the effects of 6 weeks of RE on the NMF threshold as well as strength and functional performance in older adults. METHODS: Twenty-four older adults...
Show moreAge-related deficits in muscle mass, strength, and function place an increased burden of work on existing skeletal muscle and may lead to early onset of neuromuscular fatigue (NMF) during activities of daily living. Resistance exercise (RE) is the proven method for improving neuromuscular function in healthy older adults. PURPOSE: To investigate the effects of 6 weeks of RE on the NMF threshold as well as strength and functional performance in older adults. METHODS: Twenty-four older adults were randomly assigned to 6 weeks of RE (EXE; n = 12; age 72 (&)#177; 6.3 y; BMI 28.4 kg/m2) or control (CONT; n = 12; age 70.3 (&)#177; 5.6 y; BMI 27.6 kg/m2). Body fat percent (BF%), lean mass (LM), and fat mass (FM) were measured using DEXA and participants performed a discontinuous cycle ergometer test, physical working capacity at fatigue threshold (PWCFT), to determine the onset of NMF. Functional performance was assessed by time to complete 5 chair rises (CHAIR) and walk an 8-foot course (WALK). Lower body strength was assessed by predicted 1-RM leg extension (1RM). Two-way Analysis of Variance (ANOVA; time [PRE, POST] x group [EXE and CONT]) and magnitude based inferences were used to compare dependent variables. RESULTS: RE significantly increased 1RM (35%; p = 0.001) and CHAIR (20%; p = 0.047). RE had a likely beneficial effect on WALK (15%) and a possibly beneficial effect on PWCFT (14%). There were no significant changes to LM or FM, however, women in EXE significantly decreased BF% (p = 0.020). CONCLUSION: Results suggest that RE improves measures of strength and functional performance and possibly the onset of NMF in older adults.
Show less - Date Issued
- 2013
- Identifier
- CFE0004679, ucf:49876
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004679
- Title
- Effect of Acute L-Alanyl-L-Glutamine (Sustamine) and Electrolyte Ingestion on Cognitive Function, Multiple Object Tracking and Reaction Time Following Prolonged Exercise.
- Creator
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Pruna, Gabriel, Hoffman, Jay, Stout, Jeffrey, Fragala, Maren, University of Central Florida
- Abstract / Description
-
Changes in physiological function occurring during a body water deficit may result in significant decrements in performance, cognitive function and fine motor control during exercise. This may be due to the magnitude of the body water deficit. Rehydration strategies are important to prevent these deleterious effects in performance. The purpose of this study was to examine the changes before and after prolonged exercise of an alanine-glutamine dipeptide (AG) on cognitive function and reaction...
Show moreChanges in physiological function occurring during a body water deficit may result in significant decrements in performance, cognitive function and fine motor control during exercise. This may be due to the magnitude of the body water deficit. Rehydration strategies are important to prevent these deleterious effects in performance. The purpose of this study was to examine the changes before and after prolonged exercise of an alanine-glutamine dipeptide (AG) on cognitive function and reaction time.Twelve male endurance-trained runners (age: 23.5 (&)#177; 3.7 y; height: 175.5 (&)#177; 5.4 cm; weight: 70.7 (&)#177; 7.6 kg) participated in this study. Participants were asked to run on a treadmill at 70% of their predetermined VO2max for 1 h and then run at 90% of VO2max until volitional exhaustion on four separate days (T1-T4). T1 was a dehydration trial and T2-T4 were all different hydration modalities (electrolyte drink, electrolyte drink with a low dose of AG, electrolyte drink with a high dose of AG, respectively) where the participants drank 250 mL every 15 min. Before and after each hour run, cognitive function and reaction tests were administered. Hopkins Magnitude Based Inferences were used to analyze cognitive function and reaction time data.Results showed that physical reaction time was likely faster for the low dose trial than the high dose trial. Dehydration had a possible negative effect on the number of hits in 60-sec compared to both the low and high dose trials. Comparisons between only the electrolyte drink and the high dose ingestion appeared to be possibly negative. Analysis of lower body quickness indicates that performance in both the low and high dose trials were likely improved (decreased) in comparison to the dehydration trial. Multiple object tracking analysis indicated a possible greater performance for dehydration and low dose compared to only the electrolyte drink, while there was a likely greater performance in multiple object tracking for the high dose trial compared to consumption of the electrolyte drink only. The serial subtraction test was possibly greater in the electrolyte drink trial compared to dehydration.Rehydration with the alanine-glutamine dipeptide during an hour run at a submaximal intensity appears to maintain or enhance subsequent visual reaction time in both upper and lower body activities compared to a no hydration trial. The combination of the alanine-glutamine dipeptide may have enhanced fluid and electrolyte absorption from the gut and possibly into skeletal tissue to maintain neuromuscular performance.
Show less - Date Issued
- 2014
- Identifier
- CFE0005233, ucf:50583
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005233
- Title
- Endocrine and Contralateral Muscle Responses to Short-term Unilateral Resistance Training.
- Creator
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Boone, Carleigh, Fragala, Maren, Hoffman, Jay, Stout, Jeffrey, Fukuda, David, University of Central Florida
- Abstract / Description
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PURPOSE: The purpose of this study was to examine the effects of short-term lower body unilateral resistance training on hormonal, muscle morphological, and performance measures in young men. METHODS: Seventeen healthy, untrained young men (Age: 22.8 (&)#177; 3.7 y; BMI: 26.5 (&)#177; 4.9 kg/m2) were randomly assigned to one of two groups (UT: 22.9 (&)#177; 4.6 y, 25.3 (&)#177; 4.2 kg/m2; CON: 24.0 (&)#177; 4.6 y, 27.7 (&)#177; 5.1 kg/m2). Resistance training consisted of 4 weeks of...
Show morePURPOSE: The purpose of this study was to examine the effects of short-term lower body unilateral resistance training on hormonal, muscle morphological, and performance measures in young men. METHODS: Seventeen healthy, untrained young men (Age: 22.8 (&)#177; 3.7 y; BMI: 26.5 (&)#177; 4.9 kg/m2) were randomly assigned to one of two groups (UT: 22.9 (&)#177; 4.6 y, 25.3 (&)#177; 4.2 kg/m2; CON: 24.0 (&)#177; 4.6 y, 27.7 (&)#177; 5.1 kg/m2). Resistance training consisted of 4 weeks of unilateral lower body and bilateral upper body exercises on 3 days per week. Each training session entailed unilateral countermovement jumps (3 (&)#215; 8), unilateral leg press (LP), bilateral chest press (CP), unilateral leg extension (LE), and bilateral low row (LR). Strength exercises were performed for 3 sets of 8-10 repetitions; lower body exercises were performed with the dominant leg only. Muscle thickness (MT), pennation angle (PA), cross-sectional area (CSA), and echo-intensity (EI) of the vastus lateralis (VL) and rectus femoris (RF) muscles of both legs was assessed via ultrasound. Fascicle length (FL) was calculated as [MT / sin(PA)]. Maximal dynamic unilateral LP and LE strength was assessed during one-repetition maximum (1RM) testing; CP and LR 1RM strength was estimated as [repetition weight/(1.0278-0.0278)(reps)]. Maximal isometric knee extensor strength was isolaterally assessed via maximal voluntary contraction (MVC) testing. Mean and peak power output (Watts) was quantified during unilateral countermovement jumps via accelerometry. Fasting concentrations of total testosterone and growth hormone were obtained at baseline (PRE), immediately post (IP), 30-minutes post (30P), and 60-minutes post (60P) during both testing exercise sessions (Pre and Post). Following the 4-week intervention, all participants' maximal dynamic and isometric strength, mean and peak power output, muscle morphology, and hormonal responses were reassessed. Performance, ultrasound, and area under the curve data were analyzed using ANCOVA to observe between-group comparisons while controlling for baseline (PRE) values. Endocrine data were analyzed using a two-way, mixed-factorial repeated-measures ANOVA. RESULTS: Participants in the UT group experienced significant strength improvements of the trained (28 to 150%) and untrained legs (12 to 160%). Training did not elicit significant improvements in maximal isometric strength or power output of the trained or untrained leg. The trained RF experienced significant increases in CSA and MT. The trained VL experienced a significant increase in CSA. Muscle size of the untrained leg was not significantly augmented. Training did not elicit changes in the acute hormonal response to exercise. CONCLUSIONS: Four weeks of unilateral lower body resistance training using the dominant leg appears sufficient to evoke strength gains of both the ipsilateral and contralateral legs. However, meaningful morphological changes were observed in the trained leg only. Differences in acute hormonal responses to resistance exercise did not appear to explain the observed differences. In addition, unilateral lower body resistance training did not appear to augment the acute endocrine response to an acute bout of resistance exercise. Current findings suggest that the cross-educational strength transfer during the early stage of training is attributable to factors other than changes in muscle morphology and circulating hormones.
Show less - Date Issued
- 2014
- Identifier
- CFE0005307, ucf:50538
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005307
- Title
- The Cross Education of Neuromuscular Economy.
- Creator
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Beyer, Kyle, Fukuda, David, Hoffman, Jay, Stout, Jeffrey, Fragala, Maren, University of Central Florida
- Abstract / Description
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Cross education is the phenomenon by which the untrained limb will experience a gain in strength following a unilateral resistance training program. However, little is known as to the underlying adaptation occurring in the untrained limb. Purpose: To examine the effect of dynamic unilateral resistance training on the strength and neuromuscular adaptations of both the trained and untrained legs. Methods: Eight previously untrained males (22.38(&)#177;2.92 y, 1.73(&)#177;0.08 m, 75.26(&)#177;14...
Show moreCross education is the phenomenon by which the untrained limb will experience a gain in strength following a unilateral resistance training program. However, little is known as to the underlying adaptation occurring in the untrained limb. Purpose: To examine the effect of dynamic unilateral resistance training on the strength and neuromuscular adaptations of both the trained and untrained legs. Methods: Eight previously untrained males (22.38(&)#177;2.92 y, 1.73(&)#177;0.08 m, 75.26(&)#177;14.53 kg) completed a four-week unilateral resistance training program, while another eight untrained males (24.00(&)#177;4.57 y, 1.84(&)#177;0.05 m, 94.21(&)#177;16.14 kg) served as controls. Isometric leg extension strength, leg press 1 repetition maximum (1RM), leg extension 1RM, root mean square of the maximal electromyographic amplitude (EMG), submaximal EMG, dynamic neuromuscular economy (NME) and the slope of NME-power output relationship were determined before and after training to assess the changes in strength and neuromuscular adaptations of the vastus lateralis (VL) and rectus femoris (RF) in both the trained and untrained legs. The unilateral resistance training program was conducted on the dominant leg (DOM) in the unilateral resistance training group (URT) and was compared to the dominant leg of the control group (CON). Cross education was measured in the nondominant leg (NON) for both groups. The unilateral resistance training program was completed three days per week for a total of twelve training sessions. Exercises included in the training program were unilateral leg press, unilateral leg extension, bilateral chest press and bilateral low row. All data was analyzed using one-way analysis of covariance of the post-testing values using the pre-testing values as the covariate. Further analysis of the EMG and NME data was performed using magnitude-based inferences. Results: The URT group improved their isometric (DOM:11.03%, NON:4.98%), leg press (DOM:77.63%, NON:64.88%) and leg extension (DOM:46.76%, NON:16.43%) strength after the four weeks of resistance training. There was no difference between the groups in isometric strength in the dominant (p=0.188) or nondominant (p=0.948) leg. For leg extension 1RM, there was a significant difference between groups in the dominant leg (p=0.018), but not the nondominant leg (p=0.482). However, there were significant group differences in both the dominant (p=0.003) and nondominant (p=0.034) leg for leg press 1RM. In terms of maximal EMG, the training groups improved in the vastus lateralis (DOM:29.81%, NON:31.44%) and rectus femoris (DOM:20.71%, NON:6.26%) individually, as well as in total EMG (DOM:24.78%, NON:17.57%). There was a Likely Positive or Very Likely Positive effect of unilateral resistance training on the changes in maximal EMG of the vastus lateralis and rectus femoris in both the dominant and nondominant legs. There was a Likely Positive effect of unilateral resistance training on the submaximal EMG of the dominant vastus lateralis at 75 and 125 watts. Conversely, in the rectus femoris, there was Unclear effects of unilateral resistance training on the submaximal EMG of the dominant leg. There was no consistent effect of unilateral resistance training on submaximal EMG values of the vastus lateralis in the nondominant leg. However, the rectus femoris in the nondominant leg experienced a Likely Positive effect of unilateral resistance training on submaximal EMG. NME improved in the URT group in the VL at 75 (DOM:9.73%, NON:13.42%), 100 (DOM:8.76%, NON:8.21%), and 125(DOM:24.26%, NON:12.8%) watts and in the RF at 75 (DOM:22.25%, NON:15.73%), 100(DOM:24.85%, NON:17.05%) and 125 (DOM:30.99%) watts. In terms of neuromuscular economy, there was a Likely Positive or Very Likely Positive effect of unilateral resistance training on most measures of NME on both the vastus lateralis and rectus femoris in both the dominant and nondominant legs. In terms of NME slope, there was only a Likely Positive effect of unilateral resistance training on the dominant vastus lateralis. Conclusion: Based on these results, it appears that the cross education of strength from unilateral resistance training is modality-specific. Furthermore, the NME of both the vastus lateralis and rectus femoris in both legs appear to improve following unilateral resistance training. However, in the nondominant leg, the improvement in NME appears to be due solely to the increase in maximal EMG, whereas the improved NME in the dominant leg is due to both an increase in maximal EMG and a decrease in submaximal EMG.
Show less - Date Issued
- 2014
- Identifier
- CFE0005305, ucf:50537
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005305
- Title
- Acute Pro-inflammatory Immune Response Following Different Resistance Exercise Protocols in Trained Men.
- Creator
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Wells, Adam, Hoffman, Jay, Stout, Jeffrey, Fukuda, David, Oliveira, Leonardo, University of Central Florida
- Abstract / Description
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The successful regeneration of muscle tissue is dependent upon the infiltration of phagocytic CD14++CD16- monocytes that support the proliferation and differentiation of myogenic precursor cells. Physiologically, the magnitude of the cellular response following resistance exercise is dictated by the level of receptor expression on the plasma membrane of the monocyte, as well as the secretion of their cognate ligands from tissue resident cells. However, it remains unclear whether the innate...
Show moreThe successful regeneration of muscle tissue is dependent upon the infiltration of phagocytic CD14++CD16- monocytes that support the proliferation and differentiation of myogenic precursor cells. Physiologically, the magnitude of the cellular response following resistance exercise is dictated by the level of receptor expression on the plasma membrane of the monocyte, as well as the secretion of their cognate ligands from tissue resident cells. However, it remains unclear whether the innate pro-inflammatory immune response varies with different resistance training protocols, and how it may impact recovery and the muscle remodeling process. Therefore, the purpose of this investigation was to examine temporal changes in the expression of chemotactic and adhesion receptors following an acute bout of high-volume, moderate-intensity (VOL) versus high-intensity, low-volume (HVY) lower-body resistance exercise in experienced, resistance trained men. Changes in receptor expression were assessed in conjunction with plasma concentrations of MCP-1, TNF?, and cortisol. Ten resistance-trained men (90.1 (&)#177; 11.3 kg; 176.0 (&)#177; 4.9 cm; 24.7 (&)#177; 3.4 yrs; 14.1 (&)#177; 6.1% body fat) performed each resistance exercise protocol in a random, counterbalanced order. Blood samples were obtained at baseline (BL), immediately (IP), 30 minutes (30P), 1 hour (1H), 2 hours (2H), and 5 hours (5H) post-exercise. Analysis of target receptor expression on CD14++CD16- monocytes was completed at BL, IP, 1H, 2H and 5H time points via flow cytometric analysis. Plasma concentrations of myoglobin, and LDH AUC were significantly greater following HVY compared to VOL (p = 0.003 and p = 0.010 respectively). Changes in plasma TNF?, MCP-1, and expression of CCR2, CD11b, and GCR on CD14++CD16- monocytes were similar following HVY and VOL. When collapsed across groups, TNF? was significantly increased at IP, 30P, 1H and 2H post-exercise (p = 0.001 (-) 0.004), while MCP-1 was significantly elevated at all post-exercise time points (p = 0.002 (-) 0.033). CCR2 expression was significantly lower at IP, 1H, 2H and 5H post-exercise (p = 0.020 (-) 0.040). In contrast, CD11b receptor expression was significantly greater at 1H relative to BL (p = 0.001), while GCR expression was not significantly different from baseline at any time point. As expected, plasma cortisol concentrations were significantly higher following VOL compared to HVY (p = 0.001), although this did not appear to be related to changes in receptor expression. Plasma testosterone concentrations and TNFr1 receptor expression did not appear to be affected by resistance exercise. Our results do not support a role for cortisol in the modulation of CCR2 receptors in vivo, while the degree of muscle damage does not appear to influence plasma concentrations of TNF?, or MCP-1. It is therefore likely that both HVY and VOL protocols constitute an exercise stimulus that is sufficient enough to promote a robust pro-inflammatory response, which is similar in timing and magnitude.
Show less - Date Issued
- 2015
- Identifier
- CFE0005736, ucf:50088
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005736
- Title
- The effect of moderate altitude on high intensity running performance during a game with collegiate female soccer players.
- Creator
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Bohner, Jonathan, Hoffman, Jay, Fragala, Maren, Stout, Jeffrey, Fukuda, David, University of Central Florida
- Abstract / Description
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Competition often requires teams that reside at sea level to compete against opponents whose residence is at a moderate altitude. This may pose a potential competitive disadvantage considering that moderate altitude may cause decrements in VO2max, distance covered, and time to exhaustion in endurance athletes. The purpose of this study was to examine the effect of altitude on game performance measures. Six NCAA Division I female soccer players (20.33 (&)#177; 1.21 y; 168 (&)#177; 6.45 cm; 62...
Show moreCompetition often requires teams that reside at sea level to compete against opponents whose residence is at a moderate altitude. This may pose a potential competitive disadvantage considering that moderate altitude may cause decrements in VO2max, distance covered, and time to exhaustion in endurance athletes. The purpose of this study was to examine the effect of altitude on game performance measures. Six NCAA Division I female soccer players (20.33 (&)#177; 1.21 y; 168 (&)#177; 6.45 cm; 62.5 (&)#177; 6.03 kg) were retrospectively examined. Comparisons were made between two competitions that were played at sea level (SL) within two weeks of a game played at a moderate altitude (1840 m) on game characteristics including high intensity running (HIR) and total distance covered (TDC). Analysis was performed on these six players who met a threshold of playing sixty or more minutes in each competition. A 10-Hz global positioning system (GPS) was used to measure distance and velocity. The rate of TDC and HIR during the game (m?min-1) and percentage of time at HIR during competition were evaluated. The two games at SL were averaged to establish baseline performance and the mean results were compared with the single game played at altitude. Paired samples t-tests were performed to determine if any mean differences existed between performance at altitude and sea level.Significant differences (p (<) 0.05) were seen in minutes played between the games at SL (74.23 (&)#177; 2.93 min) versus altitude (83.24 (&)#177; 5.27 min). The relative distance rate during the game at altitude was lower at altitude (105.77 (&)#177; 10.19 m?min-1) than at SL (120.55 (&)#177; 8.26 m?min-1). HIR rate was greater at SL (27.65 (&)#177; 9.25 m?min-1) compared to altitude (25.07 (&)#177; 7.66 m?min-1). The percent of time spent at high intensity was not significantly different (p = 0.064), yet tended to be greater at sea level (10.4 (&)#177; 3.3%) than when they performed at altitude (9.1 (&)#177;2.2%).Soccer performance at a moderate altitude appears to reduce the rate at which players run throughout the competition, as well as their rate at a high intensity. Results suggest that teams that reside at SL may be at a competitive disadvantage when competing at altitude.
Show less - Date Issued
- 2014
- Identifier
- CFE0005134, ucf:50716
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005134
- Title
- The Effect of Repeated Sprint Training in Hypoxia and Beta-Alanine Supplementation On Exercise Performance.
- Creator
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Wang, Ran, Hoffman, Jay, Fukuda, David, Stout, Jeffrey, Kang, Jie, University of Central Florida
- Abstract / Description
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The primary objective of this study was to evaluate the synergistic effects of repeated sprint training in hypoxia (RSH) and beta-alanine supplementation on performance in recreationally active men. Participants were randomly assigned to one of the following groups: hypoxia + beta-alanine (HB, n = 10), hypoxia + placebo (HP, n = 9), normoxia + beta-alanine (NB, n = 11) and normoxia + placebo (NP, n = 8). All participants completed a total of 8 training sessions (each consisting of 3 sets of 5...
Show moreThe primary objective of this study was to evaluate the synergistic effects of repeated sprint training in hypoxia (RSH) and beta-alanine supplementation on performance in recreationally active men. Participants were randomly assigned to one of the following groups: hypoxia + beta-alanine (HB, n = 10), hypoxia + placebo (HP, n = 9), normoxia + beta-alanine (NB, n = 11) and normoxia + placebo (NP, n = 8). All participants completed a total of 8 training sessions (each consisting of 3 sets of 5 (&)#215; 10-s sprints at a resistance of 7.5% of body mass, with 20-s rest intervals between sprints) over 4 weeks on a cycle ergometer either in hypoxia (Oxygen fraction: FiO2 = 14.2%) or normoxia (FiO2 = 20.9%). Participants were instructed to consume a daily dosage of 6.4g (two 800 mg tablets ingested 4 times per day at 3-4 hour intervals) of either beta-alanine or placebo. Changes in performance in a graded exercise test (GXT), repeated sprint test (RST) and 3-min all-out test (3MT) were examined before and after 28-days of training and supplementation. Aerobic performance was measured by maximal oxygen consumption (VO2max), peak power output (PPO). Exercise intolerance was assessed from critical power (CP), oxygen consumption (VO2RCP) and power output (PRCP) at respiratory compensation point. Exercise capacity was measured by total work (TW) during 3MT. Anaerobic capacity was evaluated via anaerobic working capacity (AWC), heart rate response to RST (RST_HR60) and lactate responses to RST (RST_La) and 3MT (3MT_La). Repeated sprint performance was estimated through average power output of the last sprint (RST_AP5) and all sprints (RST_AP). No between-group differences were observed for training volume or supplementation compliance. Anthropometric and hematological measures remain unchanged before and after intervention in all groups. A main effect of altitude was shown for VO2RCP, PRCP, RST_AP5, RST_HR60, and TW, with post-intervention values in the hypoxia groups significantly (p (<) 0.05) higher (lower for RST_HR60) than the normoxia groups. A main effect of beta-alanine was detected in AWC, with post-intervention values in the beta-alanine groups being significantly (p (<) 0.05) higher than the placebo groups. Results of this investigation demonstrated that RSH and beta-alanine benefit performance from different perspectives. RSH improved aerobic performance, exercise tolerance, cardiovascular recovery and exercise capacity, while beta-alanine supplementation maintained anaerobic working capacity in recreationally-trained men during the four-week repeated sprint training intervention.
Show less - Date Issued
- 2017
- Identifier
- CFE0006961, ucf:51633
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006961
- Title
- Resistance Exercise Elicits Selective Mobilization and Adhesion Characteristics of Granulocytes and Monocyte Subsets.
- Creator
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Jajtner, Adam, Hoffman, Jay, Stout, Jeffrey, Fukuda, David, Radom-Aizik, Shlomit, University of Central Florida
- Abstract / Description
-
Resistance exercise eliciting muscle damage results in an immune response, leading to increases in circulating cytokines, and immune cell mobilization. Classical monocytes respond to muscle damage, however, little is known about the intermediate or nonclassical monocyte response to resistance exercise. Moreover, the impact of polyphenol supplementation in conjunction with resistance exercise on the innate immune response is unknown. The purpose of this study was to examine the immune response...
Show moreResistance exercise eliciting muscle damage results in an immune response, leading to increases in circulating cytokines, and immune cell mobilization. Classical monocytes respond to muscle damage, however, little is known about the intermediate or nonclassical monocyte response to resistance exercise. Moreover, the impact of polyphenol supplementation in conjunction with resistance exercise on the innate immune response is unknown. The purpose of this study was to examine the immune response following resistance exercise with (PPB) and without (PL) polyphenol supplementation. Thirty-nine untrained men were randomized into three groups: PPB (n=13, 21.8(&)#177;2.5yrs, 171.2(&)#177;5.5cm, 71.2(&)#177;8.2kg), PL (n=15, 21.6(&)#177;2.5yrs, 176.5(&)#177;4.9cm, 84.0(&)#177;15.7kg) or a control group (CON) (23.3(&)#177;4.1yrs, 173.6(&)#177;12.0cm, 77.8(&)#177;15.6kg). Blood samples were obtained pre- (PRE), immediately- (IP), 1- (1H), 5- (5H), 24- (24H), 48- (48H) and 96- (96H) hours post-exercise (PPB/PL). CON rested for one hour between PRE and IP blood draws. Changes in granulocyte and monocyte subset proportions and adhesion characteristics (CD11b) were assessed via flow cytometry, while plasma cytokine concentrations and markers of muscle damage were analyzed via multiplex and spectrophotometric assays, respectively. Creatine Kinase and myoglobin were elevated at each time point for PPB and PL (p (<) 0.050). Monocyte chemoattractant protein-1 was significantly elevated at IP in PPB (p = 0.005) and PL (p = 0.006) and significantly greater than CON at 5H (PPB: p (<) 0.001; PL: p = 0.006). Granulocyte proportions were elevated at 1H (p (<) 0.001), 5H (p (<) 0.001) and 24H (p = 0.005; p = 0.006) in PPB and PL, respectively. Classical monocyte proportions were lower in PPB (p = 0.008) and PL (p = 0.003) than CON at IP, and significantly greater than CON at 1H (PPB: p = 0.002; PL: p = 0.006). Nonclassical monocyte proportions were significantly greater in PPB (p = 0.020) and PL (p = 0.028) than CON at IP. Intermediate monocyte proportions were significantly greater in PPB (p = 0.034) and PL (p = 0.001) than CON at IP, and significantly lower than CON at 1H (PPB: p = 0.003; PL: p = 0.008). Intermediate monocyte proportions were also significantly greater in PPB than CON at 24H (p = 0.016) and 48H (p = 0.007). At PRE, CD11b expression was significantly lower in the PPB group than CON and PL for intermediate (p = 0.017; p = 0.045) and nonclassical (p (<) 0.001, p = 0.019) monocytes, respectively. When groups were combined, CD11b expression was significantly elevated from PRE at IP (p (<) 0.001) and 1H (p = 0.015) on granulocytes. CD11b expression on classical monocytes was significantly elevated compared to PRE at 1H (p (<) 0.001), 5H (p = 0.033) and 24H (p = 0.004) when groups were combined. CD11b expression on intermediate monocytes was significantly elevated compared to PRE at 1H (p (<) 0.001) when groups were combined. Intermediate and nonclassical monocyte proportions also showed significant positive correlations with markers of muscle damage (r = 0.361 to 0.775, p(<)0.05). Results indicated that resistance exercise in novice lifters may elicit a selective mobilization of intermediate monocytes at 24h and 48H, and that muscle damage may be related to increases in intermediate and nonclassical monocytes. In addition, polyphenol supplementation appeared to suppress CD11b expression on monocytes to resistance exercise.
Show less - Date Issued
- 2016
- Identifier
- CFE0006119, ucf:51177
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0006119
- Title
- Do Changes in Muscle Architecture Effect Post- Activation Potentiation.
- Creator
-
Reardon, Danielle, Hoffman, Jay, Fragala, Maren, Stout, Jeffrey, Fukuda, David, University of Central Florida
- Abstract / Description
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Purpose: To examine the effect of three muscle potentiation protocols on changes in muscle architecture and the subsequent effect on jump power performance. Methods: Maximal (1RM) squat strength (Mean SD=178.3 (&)#177; 36.6kg), vertical jump power, and muscle architecture were obtained in 12 resistance trained men (25.2(&)#177;3.6y; 90.67(&)#177;12.7kg). Participants randomly completed three squatting protocols at 75% (3 x 10 reps), 90% (3 x 3 reps) or 100% (1 x 1) of their 1RM, or no workout...
Show morePurpose: To examine the effect of three muscle potentiation protocols on changes in muscle architecture and the subsequent effect on jump power performance. Methods: Maximal (1RM) squat strength (Mean SD=178.3 (&)#177; 36.6kg), vertical jump power, and muscle architecture were obtained in 12 resistance trained men (25.2(&)#177;3.6y; 90.67(&)#177;12.7kg). Participants randomly completed three squatting protocols at 75% (3 x 10 reps), 90% (3 x 3 reps) or 100% (1 x 1) of their 1RM, or no workout (CON), with each protocol being separated by one week. During each testing session ultrasound and vertical jump testing were assessed at baseline (BL), 8min post (8P) and 20min post (20P) workout. Ultrasound measures of the rectus femoris (RF) and vastus lateralis (VL) muscles included; cross sectional area (CSA) and pennation angle (PNG). Following each ultrasound, peak (PVJP) and mean (MVJP) vertical jump power (using hands for maximum jump height) were measured using an accelerometer. Results: Magnitude based inferences analysis indicated that in comparison to CON, 75% resulted in a likely greater change in RF-CSA and VL-CSA (BL-8P and BL(-)20P), 90% resulted in a likely greater RF-CSA and VL-CSA (BL(-)20P), and 100% resulted in a very likely or likely decrease in VL-PNG at BL-8P and BL(-)20P, respectively). Meanwhile, changes in PVJP and MVJP for the 75% trial was likely decreased at BL-8P and BL(-)20P; and for the 90% trial MVJP was likely decreased at BL-8P and BL(-)20P. Analysis of the magnitude of the relationships indicated a likely negative relationship between VL-PNG and MVJP (r = -0.35; p (<) 0.018) at BL-8P, while at BL(-)20P, a negative relationship was observed between PVJP and RF-CSA (r = -0.37; p (<) 0.014). Conclusion: Acute increases in muscle size and acute decreases in pennation angle did not result in any potentiation in vertical jump power measures. Although the inverse relationships observed between muscle architecture variables and power suggests a potential effect, the change in position (i.e. movement from standing to supine for ultrasound measures) may negate, as a result of potential fluid shifts or muscle relaxation, the potentiating effects of the exercise. It is also possible that the fatiguing nature of the squat protocols in trained but not competitive participants may have also contributed to the results.
Show less - Date Issued
- 2013
- Identifier
- CFE0005048, ucf:49963
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005048
- Title
- Novel Developments on the Extraction and Analysis of Polycyclic Aromatic Hydrocarbons in Environmental Samples.
- Creator
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Wilson, Walter, Campiglia, Andres, Belfield, Kevin, Rex, Matthew, Harper, James, Hoffman, Jay, University of Central Florida
- Abstract / Description
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This dissertation focuses on the development of analytical methodology for the analysis of polycyclic aromatic hydrocarbons (PAHs) in water samples. Chemical analysis of PAHs is of great environmental and toxicological importance. Many of them are highly suspect as etiological agents in human cancer. Among the hundreds of PAHs present in the environment, the U.S. Environmental Protection Agency (EPA) lists sixteen as "Consent Decree" priority pollutants. Their routine monitoring in...
Show moreThis dissertation focuses on the development of analytical methodology for the analysis of polycyclic aromatic hydrocarbons (PAHs) in water samples. Chemical analysis of PAHs is of great environmental and toxicological importance. Many of them are highly suspect as etiological agents in human cancer. Among the hundreds of PAHs present in the environment, the U.S. Environmental Protection Agency (EPA) lists sixteen as "Consent Decree" priority pollutants. Their routine monitoring in environmental samples is recommended to prevent human contamination risks.A primary route of human exposure to PAHs is the ingestion of contaminated water. The rather low PAH concentrations in water samples make the analysis of the sixteen priority pollutants particularly challenging. Current EPA methodology follows the classical pattern of sample extraction and chromatographic analysis. The method of choice for PAHs extraction and pre-concentration is solid-phase extraction (SPE). PAHs determination is carried out via high-performance liquid chromatography (HPLC) or gas chromatography/mass spectrometry (GC/MS). When HPLC is applied to highly complex samples, EPA recommends the use of GC/MS to verify compound identification and to check peak-purity of HPLC fractions. Although EPA methodology provides reliable data, the routine monitoring of numerous samples via fast, cost effective and environmentally friendly methods remains an analytical challenge. Typically, 1 L of water is processed through the SPE device in approximately 1 h. The rather large water volume and long sample processing time are recommended to reach detectable concentrations and quantitative removal of PAHs from water samples. Chromatographic elution times of 30 (-) 60 min are typical and standards must be run periodically to verify retention times. If concentrations of targeted PAHs are found to lie outside the detector's response range, the sample must be diluted (or concentrated), and the process repeated. In order to prevent environmental risks and human contamination, the routine monitoring of the sixteen EPA-PAHs is not sufficient anymore. Recent toxicological studies attribute a significant portion of the biological activity of PAH contaminated samples to the presence of high molecular weight (HMW) PAHs, i.e. PAHs with MW ? 300. Because the carcinogenic properties of HMW-PAHs differ significantly from isomer to isomer, it is of paramount importance to determine the most toxic isomers even if they are present at much lower concentrations than their less toxic isomers. Unfortunately, established methodology cannot always meet the challenge of specifically analyzing HMW-PAHs at the low concentration levels of environmental samples. The main problems that confront classic methodology arise from the relatively low concentration levels and the large number of structural isomers with very similar elution times and similar, possibly even virtually identical, fragmentation patterns. This dissertation summarizes significant improvements on various fronts. Its first original component deals with the unambiguous determination of four HMW-PAHs via laser-excited time-resolved Shpol'skii spectroscopy (LETRSS) without previous chromatographic separation. The second original component is the improvement of a relatively new PAH extraction method - solid-phase nanoextraction (SPNE) - which uses gold nanoparticles as extracting material for PAHs. The advantages of the improved SPNE procedure are demonstrated for the analysis of EPA-PAHs and HMW-PAHs in water samples via GC/MS and LETRSS, respectively.
Show less - Date Issued
- 2014
- Identifier
- CFE0005443, ucf:50384
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005443
- Title
- The Effects of High-Intensity Interval Training and 28 days of [Beta]-Hydroxy-[Beta]-Methybutyrate Supplementation on Measures of Aerobic Power and Metabolic Thresholds.
- Creator
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Robinson, Edward, Stout, Jeffrey, Hoffman, Jay, Fragala, Maren, Fukuda, David, Ferguson, Matthew, University of Central Florida
- Abstract / Description
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Purpose: To examine the effects of 28 days of ?-hydroxy-?-methylbutyrate free acid (HMB) and high-intensity interval training (HIIT) on maximal oxygen consumption (VO2peak), ventilatory threshold (VT), respiratory compensation point (RCP) and time to exhaustion (Tmax) in college-aged men and women. Methods: Healthy men and women (n=34, age and V ?O2peak= 22.7+3.1yr and 39.3+5.0 mL.kg-1.min-1, respectively) participated in this study. All participants completed a series of tests prior and...
Show morePurpose: To examine the effects of 28 days of ?-hydroxy-?-methylbutyrate free acid (HMB) and high-intensity interval training (HIIT) on maximal oxygen consumption (VO2peak), ventilatory threshold (VT), respiratory compensation point (RCP) and time to exhaustion (Tmax) in college-aged men and women. Methods: Healthy men and women (n=34, age and V ?O2peak= 22.7+3.1yr and 39.3+5.0 mL.kg-1.min-1, respectively) participated in this study. All participants completed a series of tests prior and subsequent to treatment. A maximal oxygen consumption test was performed on a cycle ergometer to assess VO2peak, Tmax, VT, and RCP. The peak power output (Ppeak), power at VT (PVT) and power at RCP (PRCP) were also recorded from this test. Twenty-six subjects completed 12 HIIT (80-120% maximal workload) exercise sessions consisting of 5-6 bouts of a 2:1 minute cycling work to rest ratio protocol over a four-week period, while eight served as controls (CTL). In double-blind fashion, the HIIT groups were assigned into either a placebo (HIIT) or 3g per day of HMB (HMB-HIIT). Body composition was measured with dual energy x-ray absorptiometry (DEXA). Outcomes were assessed by ANCOVA with posttest means adjusted for pretest differences. Results: The HMB-HIIT intervention showed significant (p(<)0.05) gains in VO2peak, VT, and PVT versus the CTL and HIIT group. Both HIIT and HMB-HIIT treatment groups demonstrated significant (p(<)0.05) improvement over CTL for Ppeak, Tmax, RCP, and PRCP with no significant difference between the treatment groups. There were no significant differences observed for any measures of body composition. An independent-samples t-test confirmed that there were no significant differences between the training volumes for the HIIT and HMB-HIIT groups. Conclusion: These findings suggest that the addition of HMB supplementation may result in greater changes in VO2peak and VT than HIIT alone. Therefore, in college-aged men and women, the use of HMB supplementation may enhance the benefits of HIIT on aerobic performance measures.
Show less - Date Issued
- 2014
- Identifier
- CFE0005240, ucf:50604
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005240
- Title
- Effect of Acute L-Alanyl-L-Glutamine (Sustamine) and Electrolyte Ingestion on Plasma Electrolytes, Physiologic Measures, and Neuromuscular Fatigue during Endurance Exercise.
- Creator
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McCormack, William, Hoffman, Jay, Stout, Jeffrey, Fragala, Maren, Virgets, Thomas, University of Central Florida
- Abstract / Description
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The purpose of this study was to compare the efficacy of two dose levels of L-Alanyl-L-Glutamine in a commercially available sports drink to the sports drink only on time to exhaustion,neuromuscular fatigue and physiological measures during prolonged endurance exercise. Twelve endurance-trained males (23.5(&)#177;3.7 yrs; 175.5(&)#177;5.4 cm; 70.7(&)#177;7.6 kg) performed four trials, each consisting of 1 hr treadmill runs at 75% of VO2peak followed by a run to exhaustion at 90% of VO2peak....
Show moreThe purpose of this study was to compare the efficacy of two dose levels of L-Alanyl-L-Glutamine in a commercially available sports drink to the sports drink only on time to exhaustion,neuromuscular fatigue and physiological measures during prolonged endurance exercise. Twelve endurance-trained males (23.5(&)#177;3.7 yrs; 175.5(&)#177;5.4 cm; 70.7(&)#177;7.6 kg) performed four trials, each consisting of 1 hr treadmill runs at 75% of VO2peak followed by a run to exhaustion at 90% of VO2peak. The trials differed in type of hydration. One trial consisted of no hydration (NHY),another required ingestion of only a sports drink (ET), and two trials required ingestion of a low dose (LD) (300 mg?500 ml-1) and high dose (HD) of L-Alanyl-L-Glutamine (1 g?500 ml-1) mixedin the sports drink. During the fluid ingestion trials 250 ml were consumed every 15 min. Plasmaglutamine, glucose, electrolytes, and osmolality were measured prior to the run (PRE), and at 30, 45, and 60 min. VO2, RQ, and HR were measured every 15 min and surface electromyography (EMG) of the vastus lateralis and rectus femoris were measured every 10 min during the 1 hr run. Time to exhaustion was significantly longer during the LD and HD trials compared with NHY. Plasma glutamine concentrations were significantly elevated at 45 min in LD and HD trials, and remained elevated at 60 min during HD. Sodium concentrations increased with the beginning of exercise and remained stable for the duration of the 1 hr run. At 60 min plasma sodium was significantly lower in all trials compared with NHY. The results from this study indicated that ingestion of the alanine-glutamine dipeptide at either the low or high dose significantly improved time to exhaustion during high intensity exercise compared to a no hydration trial. These differences were not noted between ET and NHY.
Show less - Date Issued
- 2014
- Identifier
- CFE0005209, ucf:50649
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005209
