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The Effect of Training Intensity on VO2max in Young Healthy Adults: A Meta-Regression and Meta-Analysis.

Scribbans TD, Vecsey S, Hankinson PB, Foster WS, Gurd BJ - Int J Exerc Sci (2016)

Bottom Line: These studies were also divided into 3 tertiles based on intensity (tertile 1: ~60-70%; 2: ~80-92.5%; 3: ~100-250%VO2max), for comparison using separate meta-analyses.The fixed and random effects meta-regression models examining training intensity, session dose, baseline VO2max and total training volume was non-significant (Q4=1.36; p=0.85; R(2)=0.05).There was no significant difference between tertiles in mean change in VO2max (tertile 1:+0.29±0.15 l/min, ES (effect size) =0.77; 2:+0.26±0.10 l/min, ES=0.68; 3:+0.35±0.17 l/min, ES=0.80), despite significant (p<0.05) reductions in session dose and total training volume as training intensity increased.

View Article: PubMed Central - PubMed

Affiliation: School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada.

ABSTRACT

Exercise training at a variety of intensities increases maximal oxygen uptake (VO2max), the strongest predictor of cardiovascular and all-cause mortality. The purpose of the present study was to perform a systematic review, meta-regression and meta-analysis of available literature to determine if a dose-response relationship exists between exercise intensity and training-induced increases in VO2max in young healthy adults. Twenty-eight studies involving human participants (Mean age: 23±1 yr; Mean VO2max: 3.4±0.8 l·min(-1)) were included in the meta-regression with exercise training intensity, session dose, baseline VO2max, and total training volume used as covariates. These studies were also divided into 3 tertiles based on intensity (tertile 1: ~60-70%; 2: ~80-92.5%; 3: ~100-250%VO2max), for comparison using separate meta-analyses. The fixed and random effects meta-regression models examining training intensity, session dose, baseline VO2max and total training volume was non-significant (Q4=1.36; p=0.85; R(2)=0.05). There was no significant difference between tertiles in mean change in VO2max (tertile 1:+0.29±0.15 l/min, ES (effect size) =0.77; 2:+0.26±0.10 l/min, ES=0.68; 3:+0.35±0.17 l/min, ES=0.80), despite significant (p<0.05) reductions in session dose and total training volume as training intensity increased. These data suggest that exercise training intensity has no effect on the magnitude of training-induced increases in maximal oxygen uptake in young healthy human participants, but similar adaptations can be achieved in low training doses at higher exercise intensities than higher training doses of lower intensity (endurance training).

No MeSH data available.


Funnel plot of Cohen’s d effect sizes and standard error for the 40 study groups included. Mean effect size represented by the solid bar with upper and lower 95% confidence intervals represented by the dashed lines.
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f2-ijes_09_02_230: Funnel plot of Cohen’s d effect sizes and standard error for the 40 study groups included. Mean effect size represented by the solid bar with upper and lower 95% confidence intervals represented by the dashed lines.

Mentions: In order to determine whether exercise training intensity, session dose, total training volume, or baseline VO2max explain heterogeneity of training effects between the 28 studies examined (40 training groups), we performed a meta-regression using these training characteristics as covariates as described by Pigott (44) (Supplementary File S1). A random-effects model was chosen as we believed that the variation among effect sizes could not be explained by sampling error alone; additionally, a random-effects model analysis is more appropriate (20), particularly for the analysis of continuous variables (e.g. exercise intensity, training volume, etc.) (34). Both fixed and random effects meta-regression analysis was performed using weighted mean effect sizes (T) and fixed-effects inverse variance weights (w) in SPSS 20.0 (SPSS, Chicago, IL, USA) using macros created by Wilson (58). Statistical significance for all regression analysis was accepted at p<0.05. A funnel plot was also constructed in GraphPad Prism v 5.01 (GraphPad Software Inc., La Jolla, CA) using the upper and lower 95% confidence intervals and effect size in order to evaluate the possibility of publication bias (Fig. 2).


The Effect of Training Intensity on VO2max in Young Healthy Adults: A Meta-Regression and Meta-Analysis.

Scribbans TD, Vecsey S, Hankinson PB, Foster WS, Gurd BJ - Int J Exerc Sci (2016)

Funnel plot of Cohen’s d effect sizes and standard error for the 40 study groups included. Mean effect size represented by the solid bar with upper and lower 95% confidence intervals represented by the dashed lines.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4836566&req=5

f2-ijes_09_02_230: Funnel plot of Cohen’s d effect sizes and standard error for the 40 study groups included. Mean effect size represented by the solid bar with upper and lower 95% confidence intervals represented by the dashed lines.
Mentions: In order to determine whether exercise training intensity, session dose, total training volume, or baseline VO2max explain heterogeneity of training effects between the 28 studies examined (40 training groups), we performed a meta-regression using these training characteristics as covariates as described by Pigott (44) (Supplementary File S1). A random-effects model was chosen as we believed that the variation among effect sizes could not be explained by sampling error alone; additionally, a random-effects model analysis is more appropriate (20), particularly for the analysis of continuous variables (e.g. exercise intensity, training volume, etc.) (34). Both fixed and random effects meta-regression analysis was performed using weighted mean effect sizes (T) and fixed-effects inverse variance weights (w) in SPSS 20.0 (SPSS, Chicago, IL, USA) using macros created by Wilson (58). Statistical significance for all regression analysis was accepted at p<0.05. A funnel plot was also constructed in GraphPad Prism v 5.01 (GraphPad Software Inc., La Jolla, CA) using the upper and lower 95% confidence intervals and effect size in order to evaluate the possibility of publication bias (Fig. 2).

Bottom Line: These studies were also divided into 3 tertiles based on intensity (tertile 1: ~60-70%; 2: ~80-92.5%; 3: ~100-250%VO2max), for comparison using separate meta-analyses.The fixed and random effects meta-regression models examining training intensity, session dose, baseline VO2max and total training volume was non-significant (Q4=1.36; p=0.85; R(2)=0.05).There was no significant difference between tertiles in mean change in VO2max (tertile 1:+0.29±0.15 l/min, ES (effect size) =0.77; 2:+0.26±0.10 l/min, ES=0.68; 3:+0.35±0.17 l/min, ES=0.80), despite significant (p<0.05) reductions in session dose and total training volume as training intensity increased.

View Article: PubMed Central - PubMed

Affiliation: School of Kinesiology and Health Studies, Queen's University, Kingston, Ontario, Canada.

ABSTRACT

Exercise training at a variety of intensities increases maximal oxygen uptake (VO2max), the strongest predictor of cardiovascular and all-cause mortality. The purpose of the present study was to perform a systematic review, meta-regression and meta-analysis of available literature to determine if a dose-response relationship exists between exercise intensity and training-induced increases in VO2max in young healthy adults. Twenty-eight studies involving human participants (Mean age: 23±1 yr; Mean VO2max: 3.4±0.8 l·min(-1)) were included in the meta-regression with exercise training intensity, session dose, baseline VO2max, and total training volume used as covariates. These studies were also divided into 3 tertiles based on intensity (tertile 1: ~60-70%; 2: ~80-92.5%; 3: ~100-250%VO2max), for comparison using separate meta-analyses. The fixed and random effects meta-regression models examining training intensity, session dose, baseline VO2max and total training volume was non-significant (Q4=1.36; p=0.85; R(2)=0.05). There was no significant difference between tertiles in mean change in VO2max (tertile 1:+0.29±0.15 l/min, ES (effect size) =0.77; 2:+0.26±0.10 l/min, ES=0.68; 3:+0.35±0.17 l/min, ES=0.80), despite significant (p<0.05) reductions in session dose and total training volume as training intensity increased. These data suggest that exercise training intensity has no effect on the magnitude of training-induced increases in maximal oxygen uptake in young healthy human participants, but similar adaptations can be achieved in low training doses at higher exercise intensities than higher training doses of lower intensity (endurance training).

No MeSH data available.