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Effects of Heat Acclimation and Acclimatisation on Maximal Aerobic Capacity Compared to Exercise Alone in Both Thermoneutral and Hot Environments: A MetaâAnalysis
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Link: https://rdcu.be/cjaZe
I">https://rdcu.be/cjaZe&quo... read this paper with great interest.
[
Link: https://rdcu.be/cjaZe
I">https://rdcu.be/cjaZe&quo... read this paper with great interest.
The paper focuses on several questions. However, this short thread will focus on oneâthe effect of heat acclimation on maximal capacity in thermoneutral conditions.
The paper concludes that there was a higher (small) improvement in VO2max performance in a HA compared to control, with a std. mean difference of 0.30, 95% CI = 0.06 to 0.54.
I am of the opinion that this result is inaccurate, and I explain why below.
I am of the opinion that this result is inaccurate, and I explain why below.
A fixed-effects-model was chosen for the original analysis. This assumes that âall studies along with their effect sizes stem from a single homogeneous populationâ.
However, the studies included men and women, and participants with a variety of sport backgrounds, including table tennis and cycling, in addition to military personnel. In this context, a random-effect model is likely more appropriate. https://bookdown.org/MathiasHarrer/Doing_Meta_Analysis_in_R/random.html">https://bookdown.org/MathiasHa...
There are also instances of double counting, studies: Gore (1997), Willmott (2018) and Schvartz (1977).
https://handbook-5-1.cochrane.org/chapter_16/16_5_4_how_to_include_multiple_groups_from_one_study.htm">https://handbook-5-1.cochrane.org/chapter_1...
https://handbook-5-1.cochrane.org/chapter_16/16_5_4_how_to_include_multiple_groups_from_one_study.htm">https://handbook-5-1.cochrane.org/chapter_1...
After selecting a random-effects-model and correcting for double counting of studies, the substantive conclusion changesâthere is no evidence that HA has an effect on VO2max performance (in thermoneutral conditions), with a SMD of 0.06, 95% CI = -0.56 to 0.44.
I considered more closely the study by Schvartz (1977), where three groups (n=7 each group) of men with different VO2max capacities were recruited.
This study had a relatively strong influence on the effect size, but not the substantive conclusion of my analysis. However, âno effectâ is now perhaps less convincing, as the SMD without this study was -0.24, 95% CI = -0.63 to 0.15.
I have had to make some assumptions, as the data and code were not made available with the paper. The data and code used to produce the analysis in this tweet can be found at: https://github.com/SciBorgo/effect-of-ha-on-vo2max-performance">https://github.com/SciBorgo/...
