TY - JOUR
T1 - Individual physiological and mitochondrial responses during 12 weeks of intensified exercise
AU - Jacques, Macsue
AU - Landen, Shanie
AU - Alvarez Romero, Javier
AU - Yan, Xu
AU - Garnham, Andrew
AU - Hiam, Danielle
AU - Siegwald, Mélina
AU - Mercier, Emma
AU - Hecksteden, Anne
AU - Eynon, Nir
AU - Voisin, Sarah
N1 - Funding Information:
We are grateful for the support of the Australian National Health & Medical Research Council (NHMRC) via Nir Eynon’s Career Development Fellowship (APP1140644) & Sarah Voisin’s Early Career Research Fellowship (APP11577321). We also thank the Australian Research Council (ARC) for supporting the Gene SMART study (DP190103081).
Funding Information:
We are grateful for the support of the Australian National Health & Medical Research Council (NHMRC) via Nir Eynon?s Career Development Fellowship (APP1140644) & Sarah Voisin?s Early Career Research Fellowship (APP11577321). We also thank the Australian Research Council (ARC) for supporting the Gene SMART study (DP190103081). We would like to thank Dr Andrew Philip, from the Garvan Institute, Sydney, Australia for his contribution revising this paper and adding of suggestions. Results of this study are presented clearly, honestly, and without fabrication, falsification, or inappropriate data manipulation, and statement that results of the present study do not constitute endorsement by ACSM.
Publisher Copyright:
© 2021 The Authors. Physiological Reports published by Wiley Periodicals LLC on behalf of The Physiological Society and the American Physiological Society
PY - 2021/8
Y1 - 2021/8
N2 - Aim: Observed effects of exercise are highly variable between individuals, and subject-by-training interaction (i.e., individual response variability) is often not estimated. Here, we measured mitochondrial (citrate synthetase, cytochrome-c oxidase, succinate dehydrogenase, and mitochondrial copy-number), performance markers (Wpeak, lactate threshold [LT], and VO2peak), and fiber type proportions/expression (type I, type IIa, and type IIx) in multiple time points during 12-week of high-intensity interval training (HIIT) to investigate effects of exercise at the individual level. Methods: Sixteen young (age: 33.1 ± 9.0 years), healthy men (VO2peak 35–60 ml/min/kg and BMI: 26.4 ± 4.2) from the Gene SMART study completed 12-week of progressive HIIT. Performance markers and muscle biopsies were collected every 4 weeks. We used mixed-models and bivariate growth models to quantify individual response and to estimate correlations between variables. Results: All performance markers exhibited significant (Wpeak 0.56 ± 0.33 p = 0.003, LT 0.37 ± 0.35 p = 0.007, VO2peak 3.81 ± 6.13 p = 0.02) increases overtime, with subject-by-training interaction being present (95% CI: Wpeak 0.09–0.24, LT 0.06–0.18, VO2peak 0.27–2.32). All other measurements did not exhibit significant changes. Fiber type IIa proportions at baseline was significantly associated with all physiological variables (p < 0.05), and citrate synthetase and cytochrome-c oxidase levels at baseline and overtime (i.e., intercept and slope) presented significant covariance (p < 0.05). Finally, low correlations between performance and mitochondrial markers were observed. Conclusion: We identified a significant subject-by-training interaction for the performance markers. While for all other measures within-subject variability was too large and interindividual differences in training efficacy could not be verified. Changes in measurements in response to exercise were not correlated, and such disconnection should be further investigated by future studies.
AB - Aim: Observed effects of exercise are highly variable between individuals, and subject-by-training interaction (i.e., individual response variability) is often not estimated. Here, we measured mitochondrial (citrate synthetase, cytochrome-c oxidase, succinate dehydrogenase, and mitochondrial copy-number), performance markers (Wpeak, lactate threshold [LT], and VO2peak), and fiber type proportions/expression (type I, type IIa, and type IIx) in multiple time points during 12-week of high-intensity interval training (HIIT) to investigate effects of exercise at the individual level. Methods: Sixteen young (age: 33.1 ± 9.0 years), healthy men (VO2peak 35–60 ml/min/kg and BMI: 26.4 ± 4.2) from the Gene SMART study completed 12-week of progressive HIIT. Performance markers and muscle biopsies were collected every 4 weeks. We used mixed-models and bivariate growth models to quantify individual response and to estimate correlations between variables. Results: All performance markers exhibited significant (Wpeak 0.56 ± 0.33 p = 0.003, LT 0.37 ± 0.35 p = 0.007, VO2peak 3.81 ± 6.13 p = 0.02) increases overtime, with subject-by-training interaction being present (95% CI: Wpeak 0.09–0.24, LT 0.06–0.18, VO2peak 0.27–2.32). All other measurements did not exhibit significant changes. Fiber type IIa proportions at baseline was significantly associated with all physiological variables (p < 0.05), and citrate synthetase and cytochrome-c oxidase levels at baseline and overtime (i.e., intercept and slope) presented significant covariance (p < 0.05). Finally, low correlations between performance and mitochondrial markers were observed. Conclusion: We identified a significant subject-by-training interaction for the performance markers. While for all other measures within-subject variability was too large and interindividual differences in training efficacy could not be verified. Changes in measurements in response to exercise were not correlated, and such disconnection should be further investigated by future studies.
KW - exercise
KW - mitochondria
KW - training variability
KW - VO
UR - http://www.scopus.com/inward/record.url?scp=85112384146&partnerID=8YFLogxK
U2 - 10.14814/phy2.14962
DO - 10.14814/phy2.14962
M3 - Article
C2 - 34327858
AN - SCOPUS:85112384146
SN - 2051-817X
VL - 9
JO - Physiological Reports
JF - Physiological Reports
IS - 15
M1 - e14962
ER -