Abstract
Previous studies have examined the effects of sleep deprivation on psychomotor abilities. However, there is a lack of research specifically addressing the effects of sleep deprivation, cognitive function and core body temperature. The extent to which fatigue and temperature will impair psychomotor abilities remains unclear.
PURPOSE: The purpose of this study was to examine the effects of tympanic temperature and duration of exercise on the number and magnitude of minor lapses experienced in a Psychomotor Vigilance Test (PVT) during a 36 endurance event.
METHODS: 9 male and 3 female participants took part in a 36-hour sustained endurance event without sleep (N = 12, Mean age = 31.8 ± 5.0 yrs). The participants completed a Leisure Physical Activity Survey prior to the event (Total Aerobic Exercise Score = 7.1 ± .1.8, Mean Total Weightlifting Score = 6.7 ± 1.9) with results suggesting high levels of physical activity. Participants were stopped for data collection at checkpoints throughout the 36 hour event. Tympanic temperatures were assessed with a Genius™ 2 Tympanic thermometer (Covidien LLC) as well as time of day in relation to the race was recorded, and a Walter Reed Psychomotor Vigilance Test (PVT) was administered at each data collection.
RESULTS: General Linear Model analysis was conducted to predict minor lapses in attention (Omnibus Test p<.001) and resulted in significant main effects for Tympanic Temperature (p<.001), Day of the Competition (p=0.018) and a Tympanic Temperature*Day of Competition interaction (p<.001). During the 36 hours of the endurance event the participants Tympanic Temperature declined (Day 1: 38.0±0.7 degrees Celsius, Day 2: 37.7±1.0 Degrees Celsius, Day 3: 36.6±0.7 Degrees Celsius) and was associated with an increase in lapses in attention (Day 1: 5.7± 4.3 lapses, Day 2: 6.6± 5.7 lapses, Day 3: 13.0± 7.5 lapses).
CONCLUSIONS: Both sleep deprivation and reduced core body temperature from sustained exercise contributed to a decrease in psychomotor ability. With sustained endurance events becoming more popular the effects of such events on cognitive function is an area that warrants further investigation.