To investigate the influence of different intensities and durations of exercise before bedtime on the sleep pattern and core body temperature of individuals considered good sleepers, we selected 17 healthy males and all underwent 5 nonconsecutive days of study. Measurements of polysomnographic parameters and core body temperature were taken at baseline and after each experimental protocol, performed at night. We found increased sleep efficiency (p = .016) among all protocols compared with baseline data and increase in REM sleep latency (p = .047) between two experiments; there was decrease in the percentage of stage 1 sleep (p = .046) and wake after sleep onset (p = .003). Core body temperature did not change significantly during the nights following exercise. Exercise performed before sleep does not impair sleep quality; rather, its practice improves sleep in good sleepers who are nonathletes, and may be considered to improve sleep pattern.