| The purpose of the study was to compare exercise performance, cardiovascular, and thermoregulatory responses in a sample of wheelchair athletes during moderate intensity and duration exercise in environments with varying temperature and humidity. Four male participants, with varying disabilities (i.e., low level [n = 2] and high level SCI [n = 1], and lower limb amputation [n = 1]) participated in the study.; Participants performed four testing sessions: one maximal test to determine exercise intensity for experimental sessions; and three sessions involving 30 min of arm crank ergometry exercise at an intensity of 60% physical work capacity (PWC), followed by a 30 s ramping protocol to volitional fatigue. Experimental conditions were: thereto-neutral (21.2°C, 50% relative humidity, or wet bulb globe temperature (WGBT) 17.60°C); hot thermal-stress (36.7°C, 30% relative humidity, or WBGT 28°C); and hot and humid thermal-stress (32.2°C, 70% relative humidity, or WBGT 28°C).; Differences between the three experimental conditions for all dependent variables were analyzed employing Friedman multiple comparison nonparametric analyses. Statistical decisions were determined using an alpha level set at p = .05. In the presence of statistical significance, a Freidman post-hoc analysis was used to determine existence of significant differences between experimental conditions.; Humidity lowered time to exhaustion and power output, and increased aural temperature (P ≤ .05) to a greater degree during exercise to volitional fatigue than other environments. Humidity also increased heart rate and physical strain to a greater extent (P ≤ .05) during exercise. Mean and regional skin temperatures during rest, exercise, and post-ramping exercise were consistently higher (P ≤ .05) only in the high ambient temperature environment.; In conclusion, high humidity had the greatest negative effects on exercise performance in wheelchair athletes through disruptions in cardiovascular and thermoregulatory responses. In contrast, higher ambient temperature had the greatest negative effect on mean and regional skin temperatures during rest. |
