Effect of warm-up and precooling on pacing during a 15-km cycling time trial in the heat

Int J Sports Physiol Perform. 2013 May;8(3):307-11. doi: 10.1123/ijspp.8.3.307. Epub 2012 Oct 2.


Purpose: The best way to apply precooling for endurance exercise in the heat is still unclear. The authors analyzed the effect of different preparation regimens on pacing during a 15-km cycling time trial in the heat.

Methods: Ten male subjects completed four 15-km time trials (30°C), preceded by different preparation regimes: 10 min cycling (WARM-UP), 30 min scalp cooling of which 10 min was cycling (SC+WARM-UP), ice-slurry ingestion (ICE), and ice slurry ingestion + 30 min scalp cooling (SC+ICE).

Results: No differences were observed in finish time and mean power output, although power output was lower for WARM-UP than for SC+ICE during km 13-14 (17 ± 16 and 19 ± 14 W, respectively) and for ICE during km 13 (16 ± 16 W). Rectal temperature at the start of the time trial was lower for both ICE conditions (~36.7°C) than both WARMUP conditions (~37.1°C) and remained lower during the first part of the trial. Skin temperature and thermal sensation were lower at the start for SC+ICE.

Conclusions: The preparation regimen providing the lowest body-heat content and sensation of coolness at the start (SC+ICE) was most beneficial for pacing during the latter stages of the time trial, although overall performance did not differ.

MeSH terms

  • Adult
  • Athletic Performance / physiology*
  • Bicycling / physiology*
  • Body Temperature / physiology*
  • Body Temperature Regulation / physiology*
  • Cryotherapy / methods*
  • Hot Temperature
  • Humans
  • Ice
  • Male
  • Physical Exertion / physiology
  • Scalp / physiology
  • Skin Temperature / physiology
  • Time Factors
  • Young Adult


  • Ice