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Looking ahead of 2021 Tokyo Summer Olympic Games: How Does Humid Heat Affect Endurance Performance? Insight into physiological mechanism and heat-related illness prevention strategies.

PMID 34420619 (2021): heat acclimation — Performance in heat (study note for endurance athletes).

Last updated/Feb 23, 2026, 10:34 PM

Study note • PMID 34420619

Looking ahead of 2021 Tokyo Summer Olympic Games: How Does Humid Heat Affect Endurance Performance? Insight into physiological mechanism and heat-related illness prevention strategies.

Journal of thermal biology2021 • DOI 10.1016/j.jtherbio.2021.102975
Evidence C60/100
Action 2: Consider

Worth trying if it fits your goal and context.

ELI5

In plain language

The combination of high humidity and ambient temperature of the 2021 Tokyo Summer Olympic Game will undoubtfully result in greater physiological strains and thereby downregulates the endurance performance of athletes. (expert consensus / guideline; athletes).

In this expert consensus / guideline, the abstract is mixed or unclear for Performance in heat. Treat this as a signal, not a guarantee; confirm methods and context in the full paper.

Takeaways

What the abstract suggests

  • Study question: The combination of high humidity and ambient temperature of the 2021 Tokyo Summer Olympic Game will undoubtfully result in greater physiological strains and thereby downregulates the endurance performance of athletes.
  • In this expert consensus / guideline, the abstract is mixed or unclear for Performance in heat.
  • Population: athletes.
  • Protocol cues: abstract may omit dose/timing; use the full paper to replicate accurately.

Protocol

Protocol (as reported)

  • Intervention/exposure: heat acclimation.
  • Dose/time/duration: abstract doesn’t include enough detail; use the full paper’s methods section.
  • Outcomes: Performance in heat.
  • Replication note: abstracts often omit adherence and timing; confirm details before changing training or supplementation.

Fit

Who it helps, and who should skip it

Who it helps

  • Athletes similar to the study population (athletes) working on heat.
  • Athletes who can measure Performance in heat with a repeatable workout or time-trial effort.

Who should skip

  • If you have symptoms or conditions that make the intervention risky, get professional guidance.
  • If you’re near race day and can’t safely test, defer the experiment.

Methods

What the study actually did

  • Design: expert consensus / guideline.
  • Population: athletes.
  • Outcomes measured: Performance in heat.
  • Source: PubMed PMID 34420619 (2021) — Journal of thermal biology.

Results excerpt

What the abstract reports

Therefore, the purposes of this review are: 1) to provide a clear evidence that humid heat is more stressful than dry heat for both male and female athletes and therefore the preparation for the Tokyo Summer Olympic should be environmental specific instead of…

Note: excerpts are short; for full context, read the paper.

Limits

Limitations & bias

  • Abstract-only summaries can miss critical details (population, protocol, adherence, and context).
  • Reviews and consensus statements mix protocols and populations; recommendations may not match your exact constraints.
  • If your context differs (elite vs recreational; cycling vs running), adjust expectations and be conservative.
  • This is performance information, not medical advice.

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Sources