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The Reproducibility and Validity of Using the Dmax Method to Predict Physical Working Capacity at Fatigue Threshold

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Date Issued:
2016
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 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.
Title: The Reproducibility and Validity of Using the Dmax Method to Predict Physical Working Capacity at Fatigue Threshold.
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Name(s): Riffe, Joshua, Author
Stout, Jeffrey, Committee Chair
Hoffman, Jay, Committee Member
Fukuda, David, Committee Member
University of Central Florida, Degree Grantor
Type of Resource: text
Date Issued: 2016
Publisher: University of Central Florida
Language(s): English
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 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.
Identifier: CFE0006168 (IID), ucf:51155 (fedora)
Note(s): 2016-05-01
M.S.
Education and Human Performance, Educational and Human Sciences
Masters
This record was generated from author submitted information.
Subject(s): Neuromuscular Fatigue -- Reproducibility -- Validity -- Sensitivity -- Electromyography -- High intensity interval training
Persistent Link to This Record: http://purl.flvc.org/ucf/fd/CFE0006168
Restrictions on Access: public 2016-05-15
Host Institution: UCF

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