Impaired cardiorespiratory responses when wearing an upper body compression garment during recovery in a hot environment (40 ºC).

Background: Previous studies have not investigated the effects of a heat dissipating upper body compression garment (UBCG) during cycling in a hot environment. The present study examined the effects of a heat dissipating UBCG on thermoregulatory, cardiorespiratory and perceptual responses (thermal sensation and exertion scales), during cycling at a fixed workload (~50% VO2peak) and during active recovery (~25% VO2peak).

Methods: Thirteen untrained males (mean±SD; age 21±6 years, VO2peak 53.7±5.0 ml·kg-1·min-1) completed two randomized cycling trials consisting of a 5 min rest on a cycling ergometer, followed by 4 bouts of 14 min at a fixed load + 1 min active recovery. Followed further by 10 min of active recovery. Testing occurred in a hot environment (~40±0.4 ºC, 35±2 % relative humidity, ~2.5 m·s-1 air velocity) and volunteers wore either a UBCG or non-UBCG (CON).

Results: Wearing UBCG resulted in significantly smaller reduction in heart rate (31±11 bpm vs. 46±15 bpm) and higher VO2 and VCO2 values (P<0.05) during 10 min recovery period. No differences in rectal, skin and body temperature were observed during the trial between garment conditions. Clothing wetness sensation remained significantly higher wearing CON (P<0.05) during exercise although no significant differences in weight loss or in sweat rate were observed.

Conclusions: These results suggest that wearing heat dissipating UBCG had no thermoregulatory benefits during exercise and it had impaired cardiorespiratory responses during active recovery when exercising in a hot environment.