Shift work and night work inverts activity/rest patterns and affects millions of workers. Sleep loss is one of three major shift work-related health problems and leads to daytime sleepiness and workplace accidents. Shift workers are the second highest group at risk for car accidents due to sleepiness. Research is needed to identify possible strategies to counter the effects of shift work, specifically night work and reduce accidents due to sleepiness. We hypothesize that moderate exercise (30-minutes at 0400) or a 30-minute nap may act as counter measures to sleepiness during and following night time wakefulness.

             This study will test this hypothesis with eight healthy subjects (2 groups of four) under three night shift conditions. Each subject will complete two 96-hour experiments which include two 9-hour night shifts. Researchers will collect data on activity, alertness, sleepiness and temperature at the beginning of the experiment and periodically through out the procedure. Each subject will experience all three conditions (no-treatment, exercise and nap); however, subjects will randomly be assigned to the two groups and the three experimental conditions. This pilot study will allow us to assess the effectiveness of these two treatments (exercise and naps) compared to no-treatment. The anticipated effects of the two 30-minute treatments (moderate exercise or napping) are improved alertness, less sleepiness, higher body temperature and more activity. This study will offer information of the effectiveness of exercise and naps as possible countermeasures to night time and post shift sleepiness. Findings will be used to calculate effect size and power for each treatment and to determine sample size needed for future studies.

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