Effects of Precooling on 30-km Cycling Performance and Pacing in Hot and Temperate Environments

Abstract

This study examined the effects of precooling on performance and pacing during 30-km cycling exercise in hot and temperate environments. 8 trained male cyclists performed 4 trials involving either cooling (PREC and PREC) or no-cooling interventions (TEMP and HOT) prior to a 30-km self-paced cycling exercise in either a hot (35°C, 68% relative humidity) or temperate environment (24°C, 68% relative humidity). Exercise time was longer in HOT (60.62±3.47 min) than in TEMP (58.28±3.30 min; <0.001), and precooling attenuated this thermal strain performance impairment (PREC 58.28±3.30 min; =0.048), but it was still impaired compared with TEMP (=0.02). Exercise performance in PREC (54.58±4.35 min) was no different from TEMP. Initial power output was sustained until the end of the exercise in both TEMP and PREC, but was reduced from the 12 km until the end of the trial in HOT (P<0.05). This reduction was delayed by precooling because power output was reduced only after the 20 km during PREC (P<0.05). Heart rate was similar in all conditions throughout almost the entire exercise, suggesting the maintenance of similar relative intensities. In conclusion, precooling was effective in attenuating, but not completely reversing thermal strain performance impairment and offered no ergogenic effect in the temperate environment.

A Matter of Degrees: A Systematic Review of the Ergogenic Effect of Pre-Cooling in Highly Trained Athletes

“…Concerning individual techniques, CWI showed the best results among the external strategies in terms of sports performance, offering significant increases in total distance covered [21,33,37], as well as reductions in completion time [38]. Although these previous results support the fact that cooling a larger body surface area improves performance to a greater extent, the application of ice packs alone on quadriceps and hamstrings also yielded significant positive effects in completion time after performing a 5000m treadmill time-trial [22].…”

“…In addition to this, the specificity in the physiological assessment of performance may have a key role in these findings [51], as cricket players are more familiar with sprints [27] than cyclists, who are not used to performing repeated short-duration sprints (15 s) on a cycle-ergometer [39]. However, the hypothesis that cycling may not benefit from pre-cooling was discarded, as there are a considerable number of studies that have reported positive results using cooling devices prior to simulated cycling tests [18,19,24,25,30,37,38,40,41].…”

“…The average age of participants was 24.6 years (ranging between 19.9 [32] and 34.8 [22]), and the VO 2 max varied from 55.7 [33,38] to 71.6 mL/kg/min [40]. Regarding sport modality, studies included a wide variety of athletes, both individual (cyclists [18,19,24,30,[37][38][39][40][41][42], runners [20][21][22]43], triathletes [23][24][25]42], and tennis players [26]), and team-sport players (covering cricket [27][28][29], soccer [31], lacrosse [32], and other non-specified team sports [33]). Furthermore, three studies included volunteers who recreationally practice various sport activities [34][35][36].…”

“…All the studies analyzed the acute effects of pre-cooling on sports performance and compared it with non-pre-cooling controls. A total of 20 studies evaluated external techniques through 28 interventions [18][19][20][21][22][24][25][26][27][28][29][31][32][33][37][38][39][40][41]43], 8 assessed internal techniques (intake of ice or cold water) [23,30,31,[34][35][36]42,43], and 3 investigated mixed strategies (a combination of external and internal methods) [31,40,43].…”

“…• External: cold water immersion (CWI) [21,33,37,38], ice packs [22,31], iced towels [27], cooling gloves [39], ice vest/jacket [18,20,39,41], cooling garment [19], cold water over the head [43], and diverse combinations of the above techniques [24,[26][27][28][29]32,40,41].…”