This study had the following specific aims:
Aerobic Capacity Session - Aerobic capacity (VO2max) was determined by indirect calorimetry for all participants. Workloads for the experimental sessions was be determined based on this value. Subjects were tested using a rowing cycle ergometer. The load on the ergometer was increased in a graded manner until volitional fatigue was reached.
Familiarization Session - A linear relationship between Watts and O2 utilization was used to estimate workloads corresponding to 75%, 85%, and 170% of the VO2max load. During familiarization, subjects cycled for 10 minutes at the calculated 75% VO2max load while oxygen consumption was measured. Subjects continued to cycle until the desired O2 consumption range was reached and the workload was adjusted as necessary.
Experimental Sessions – Three aerobic training protocols were implemented. All experimental sessions were conducted on the cycle ergometer used for the aerobic capacity and familiarization sessions. Respiratory gas measurements were collected throughout. Each protocol was followed by 30 minutes of resting recovery to capture post-exercise sweating and oxygen consumption.
Total moisture was determined by the difference in protection difference between pre and post testing dry weight. An additional weighing occurred 30 minutes later to characterize post-exercise moisture production. Respiratory water production was calculated based the difference between expired and inspired water content assuming saturation of expired air. Sweat rate was calculated as the difference between total moisture production and respiratory water production. Oxygen consumption, CO2 production, and ventilatory rate and volume was calculated based on metabolic gas collection using the Parvo Medics software.
Results show that the 4 minute and 30 second interval protocols produce less sweat versus the continuous exercise protocol. Furthermore, sweat production correlated with work performed on the ergometer and energy expenditure during exercise. These results suggest that interval exercise is an alternative to continuous aerobic exercise for situations where moisture production must be carefully monitored to avoid condensation issues.
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