The threshold ambient temperature for the use of pre-cooling to improve cycling time trial performance
journal contributionposted on 03.08.2018 by Steve H. Faulkner, Iris Broekhuijzen, Margherita Raccuglia, Maarten Hupperets, Simon Hodder, George Havenith
Any type of content formally published in an academic journal, usually following a peer-review process.
Purpose. Cycling time trial performance can be compromised by moderate to high ambient temperatures. It has become commonplace to implement pre-cooling prior to competition to alleviate this performance decline. However, little is known about the ambient temperature threshold above which pre-cooling becomes an effective strategy for enhancing endurance performance. It was the aim of this study to investigate the effect of pre-cooling in different environmental temperatures on time trial performance. Methods. Trained cyclists completed two time trials with (COLD) and without (CON) pre-cooling using an ice-vest and sleeves ensemble in ambient temperatures of 24˚C, 27˚C and 35˚C. Results. Time trial performance faster following COLD in both 35˚C (6.2%) and 27˚C (2.6%; both P<0.05) but not 24˚C (1.2%). Magnitude based inferential statistics indicate that COLD was very likely beneficial to performance in 35˚C and likely beneficial in 27˚C and possibly beneficial in 24°C. Mean power was 2.4%, 2.5% and 5.6% higher following COLD and considered to be likely beneficial in 24°C and very likely beneficial in 27˚C and 35˚C. COLD reduced mean skin temperature throughout the warm-up and into the time trial in all ambient temperatures (P<0.05). Sweat loss was lower following COLD in 24˚C and 27˚C but not 35˚C. There was no effect of COLD on gastrointestinal temperature at any point. Conclusions. Pre-cooling with an ice-vest and sleeves is likely to have a positive effect on time trial performance at temperatures above 24˚C, with a clear relationship between ambient temperature and the magnitude of effect of pre-cooling