Self-perception of the ability to work in the cold.

Accumulating evidence of beneficial effects from physical exertion must be balanced against increased risk of cardiac arrest during performance. There is evidence that, by using such cues as heart rate, individuals can monitor their level of exertion perceptually. We undertook experiments to discover whether temperature and heart rate interact to affect self-perception when the effective temperature is moved downard from the comfort zone. In the first pilot study, 36 males practiced a new game, SwedeBall, for a period of 20 minutes. Twelve were randomly assigned to play at a temperature of 22 degrees C, another 12 to play at 0 degrees C, and the remaining 12 to play at -7 degrees C. The players showed tendencies toward an overall improvement in self-evaluations after brief practice, with more favorable responses when the temperatures were lower. In a second experiment on different days, 8 men pedaled a standard bicycle mounted as a wind trainer in a controlled environment chamber where the effective temperature was set at 26 degrees C, 8 degrees C, or -10 degrees C. The first 5-minute ride at each temperature was at a heart rate of 120 beats per minute (bpm), the second at 140 bpm, and a third at 160 bpm. We measured ratings of perceived effort (RPE), thermal impression, discomfort, perceived rate of speed, and projected endurance. The result confirmed that RPE was lowered by temperature when heart rate was constant. The data also showed that the lowered temperatures uniformly produced more favorable self-perceptions on the other four scales. The outcome is related to physiological problems that might arise when temperature depresses heart rate and reduces the experience of effort.

RCT Entities:   Population Interventions Outcomes