High intensity interval training in the heat enhances exercise-induced lipid peroxidation, but prevents protein oxidation in physically active men
Question
Does performing a short cycling HIIT program in heat, compared with a temperate environment, change exercise-induced lipid and protein oxidation and performance markers?
Summary
In young physically active men, four weeks of supervised cycling HIIT in a hot room increased peak power output but changed oxidative-stress responses differently than the same training in temperate conditions.
Methodology
- Young healthy physically active heat-acclimatized men.
- 16 participants.
- Cycle ergometer.
- Work intervals: 60 s at peak power output.
- Recovery: 75 s active recovery at 30 W.
- Intensity: Peak power output.
- About 10.75-17.5 min including warm-up.
- 3 sessions/week.
- 4 weeks.
- Randomized two-group pre-post training study
- Peak power output, and Oxidative stress were tracked.
Outcomes
Peak power
Peak power improved in the heat group but not the temperate group.
Heat group p=0.026.
Oxidative stress
Heat increased lipid peroxidation while temperate HIIT increased protein carbonyls after acute exercise.
Heat TBARS p=0.0177; control protein carbonyls p=0.0316.
Insights
- Heat makes HIIT a different physiological stimulus and should be treated as an added load.
- The interval structure is simple but intensity requires a peak-power test.
Limitations
- Small all-male sample
- Heat-acclimatized participants only
- No direct thermal strain measures during training
- Biomarker outcomes
Safety
- No adverse events were reported.
- Sessions were supervised by at least one research team member, environmental conditions were monitored, and hydration before incremental testing was standardized.
- Dropout/adherence were not reported in detail, but the text indicates both groups completed the same 12-session volume.