Long-distance triathlon glossary·THERMO

Thermoregulation: body temperature management during exercise

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The body's ability to maintain its core temperature around 37-38 degrees C during exercise through sweating and skin vasodilation.

During exercise, muscles produce 3-5x more heat than at rest. The body dissipates it mainly by evaporation (sweating, 80% of dissipation). When core temperature exceeds 38.5 degrees C, performance declines. Above 40 degrees C, exertional heat stroke becomes a critical risk. Aggravating factors: high ambient temperature, humidity above 60%, high intensity, dehydration. Precooling strategies (ice vest, cold drinks) and race cooling (water on head, sponges) delay reaching critical thresholds.

In TriPaced:

TriPaced includes a heat index in race preparation (forecast temperature and humidity) and adjusts pace targets for hot days (+15-20 s/km above 28 degrees C). The session recap flags workouts with heat-related cardiac drift.

Source Periard et al., 2021: Adaptations and mechanisms of human heat acclimation, Scandinavian Journal of Medicine & Science in Sports

Related terms

  • TSS : Training Stress Score
  • CTL : Chronic Training Load (fitness)
  • ATL : Acute Training Load (fatigue)
  • TSB : Training Stress Balance (freshness)
  • Sweet spot : the efficiency zone
  • Threshold : the upper sustainable limit