Different humidity environments do not affect the subsequent exercise ability of college football players after aerobic high-intensity interval training
Question
Do different heat and humidity environments alter recovery and subsequent exercise ability after aerobic HIIT in college football players?
Summary
In college football players, a single 4 x 4 min cycling HIIT session in hotter and more humid environments increased thermal and some physiological strain, but subsequent squat-jump and time-to-exhaustion performance fell similarly across all environments.
Methodology
- College football players completing all four environmental HIIT trials
- 12 participants.
- Cycle ergometer.
- Work intervals: 4 min.
- Recovery: 3 min active rest.
- Intensity: 90-95% HRmax work, 70% HRmax active rest.
- 4 x 4 min plus 3 min recoveries and warm-up.
- Four single-session trials.
- Crossover with 1-week washout between environments.
- Randomized controlled crossover acute environmental study
- Thermal strain, Physiological recovery, Subsequent performance, and Perceived exertion were tracked.
Outcomes
Performance
Humidity condition did not significantly change subsequent squat-jump or time-to-exhaustion performance.
Squat jump and TTE decreased after exercise in all four groups, with no significant between-environment differences
Thermal strain
Hot/humid conditions increased skin temperature and thermal sensation compared with control.
Skin temperature rose in hot groups; H80 higher at 5 and 10 min; thermal sensation greater in hot/humid conditions early in recovery
Lactate
Lactate increased after HIIT in all conditions but was lower in hot groups than control at corresponding time points.
Lactate peaked at 3 min and remained above baseline to 40 min; hot groups lower than control
HRV
Some HRV indices decreased in higher-humidity heat, but the text was not fully consistent about which indices.
the paper reports HF decreased in H40/H80; abstract also mentions RMSSD and HF decreases
Insights
- Heat/humidity may increase perceived thermal strain after HIIT without further reducing next-hour performance in trained football players.
- A standardized 4 x 4 cycling HIIT bout can be used to study recovery conditions.
- Environmental advice should distinguish physiological strain from measured performance decrement.
Limitations
- Small trained-athlete sample
- Acute laboratory chamber study
- Cycling may not match football movement demands
- College players, not elite professionals
- HRV reporting has some textual inconsistency
Safety
- The protocol used an environmental chamber and standardized recovery; specific adverse events were not reported in the the paper.