The current study aimed to examine the naturalistic relationship between physical activity and sleep by exploring frequency, type, and timing of exercise and their association with a variety of sleep variables (e.g., sleep onset latency, wake after sleep onset, sleep efficiency). Young adults (n = 1003) completed a variety of self-report questionnaires, including a week-long sleep diary and a survey of typical frequency, type, and timing of exercise completed in the past week. Increased frequency of physical activity was related to increased sleep efficiency (total sleep time/time in bed), decreased time in bed, and decreased time spent awake in bed in the morning. Greater amounts of exercise energy expenditure (i.e., metabolic equivalents) per week was related to increased sleep efficiency, and decreased time in bed and time spent awake in bed in the morning. After controlling for other factors, this relationship remained true only for time spent awake in bed in the morning. Early morning exercisers reported shorter total sleep time and time in bed than those who typically exercised at other times. No exercise differences were found between those who met the research diagnostic criteria for insomnia and those who did not. This study provides valuable information to help guide future experimental and intervention studies.