Postexercise Cooling Rates in 2 Cooling Jackets

Abstract

AbstractContext:Cooling jackets are a common method for removing stored heat accumulated during exercise. To date, the efficiency and practicality of different types of cooling jackets have received minimal investigation.Objective:To examine whether a cooling jacket containing a phase-change material (PC17) results in more rapid postexercise cooling than a gel cooling jacket and a no-jacket (control) condition.Design:Randomized, counterbalanced design with 3 experimental conditions.Setting:Participants exercised at 75% V˙o2max workload in a hot climate chamber (temperature  =  35.0 ± 1.4°C, relative humidity  =  52 ± 4%) for 30 minutes, followed by postexercise cooling for 30 minutes in cool laboratory conditions (ambient temperature  =  24.9 ± 1.8°C, relative humidity  =  39% ± 10%).Patients or Other Participants:Twelve physically active men (age  =  21.3 ± 1.1 years, height  =  182.7 ± 7.1 cm, body mass  =  76.2 ± 9.5 kg, sum of 6 skinfolds  =  50.5 ± 6.9 mm, body surface area  =  1.98 ± 0.14 m2, V˙o2max  =  49.0 ± 7.0 mL·kg−1·min−1) participated.Intervention(s):Three experimental conditions, consisting of a PC17 jacket, a gel jacket, and no jacket.Main Outcome Measure(s):Core temperature (TC), mean skin temperature (TSk), and TC cooling rate (°C/min).Results:Mean peak TC postexercise was 38.49 ± 0.42°C, 38.57 ± 0.41°C, and 38.55 ± 0.40°C for the PC17 jacket, gel jacket, and control conditions, respectively. No differences were observed in peak TC cooling rates among the PC17 jacket (0.038 ± 0.007°C/min), gel jacket (0.040 ± 0.009°C/min), and control (0.034 ± 0.010°C/min, P > .05) conditions. Between trials, no differences were calculated for mean TSk cooling.Conclusions:Similar cooling rates for all 3 conditions indicate that there is no benefit associated with wearing the PC17 or gel jacket.