Cardiorespiratory Fitness and Performance Adaptations to High-Intensity Interval Training: Are There Differences Between Men and Women? A Systematic Review with Meta-Analyses.
Level 1 - systematic review of randomized trials
Systematic review and meta-analysis of intervention trials
PubMed 37676620 · doi:10.1007/s40279-023-01914-0
What was done
A systematic review and random-effects pre-post meta-analysis searched MEDLINE, SPORTDiscus, and ProQuest through September 2022 for trials in healthy adults comparing or reporting male and female maximal oxygen uptake (VO2max) or performance adaptations to high-intensity interval training (HIIT). The review included 33 references from 28 trials (n = 965; 462 women, 503 men). Meta-analyses included 19 studies for VO2max, 8 for peak power output (PPO), and 5 for threshold power (power AT).
What was found
Primary analyses showed no significant sex differences for any outcome. VO2max improvements had identical effect sizes in women (g = 0.57; 95% CI 0.44-0.69) and men (g = 0.57; 95% CI 0.42-0.72), with raw mean changes of 0.20 L/min (3.34 mL/kg/min; 11.16% change) in women and 0.32 L/min (3.50 mL/kg/min; 10.90% change) in men. Power AT effect sizes were also identical in women (g = 0.38; 95% CI 0.13-0.64) and men (g = 0.38; 95% CI 0.11-0.64). Subgroup analysis found higher PPO effect sizes in well-trained women (g = 0.37) than well-trained men (g = 0.17), and interventions 4 weeks or less showed smaller VO2max effect sizes than longer programs (p < 0.001). Significant heterogeneity was present for VO2max and PPO (I2 range: 62.06-78.80%).
Why it matters
This review demonstrates that biological sex does not inherently alter the magnitude of cardiorespiratory fitness or threshold power gains from HIIT, indicating standard HIIT prescription guidelines apply equally to men and women.
Limits
Significant statistical heterogeneity (I2 up to 78.80%) was present across trials. Performance outcomes other than VO2max had small study counts (8 for PPO, 5 for power AT). Findings relied on pre-post single-arm changes rather than direct randomized sex comparisons, and age-subgroup findings were constrained by overlapping age categories across cohorts.
Cited by
- supports Men and women exhibit very similar physiological responses to exercise training.