Heat acclimatization does not improve VO2max or cycling performance in a cool climate in trained cyclists

Scand J Med Sci Sports. 2015 Jun:25 Suppl 1:269-76. doi: 10.1111/sms.12409.


This study investigated if well-trained cyclists improve V ˙ O 2 m a x and performance in cool conditions following heat acclimatization through natural outdoor training in hot conditions. Eighteen trained male cyclists were tested for physiological adaptations, V ˙ O 2 m a x , peak aerobic power output, exercise efficiency, and outdoor time trial (TT) performance (43.4 km in cool environment, ∼5-13 °C) before and after 2 weeks of training in a cool (CON, n = 9) or hot (∼35 °C, HA, n = 9) environment. After heat acclimatization, TT performance in the heat was improved by 16%; however, there was no change in the HA group in V ˙ O 2 m a x (4.79 ± 0.21 L/min vs 4.82 ± 0.35 L/min), peak aerobic power output (417 ± 16 W vs 422 ± 17 W), and outdoor TT performance in cool conditions (300 ± 14 W/69 ± 3 min vs 302 ± 9 W/69 ± 4 min). The present study shows that 2 weeks of heat acclimatization was associated with marked improvements in TT performance in the heat. However, for the well-trained endurance athletes, this did not transfer to an improved aerobic exercise capacity or outdoor TT performance in cool conditions.

Keywords: Maximal oxygen uptake; cycling; exercise efficiency; plasma volume; power output; time trial performance; well-trained athletes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acclimatization / physiology*
  • Adult
  • Anaerobic Threshold
  • Athletic Performance / physiology*
  • Bicycling / physiology*
  • Climate
  • Cold Temperature*
  • Hot Temperature / adverse effects*
  • Humans
  • Male
  • Oxygen Consumption / physiology*
  • Time Factors