Mixed model regression interactions between exercise condition X time on sleep latency, sleep maintenance, percentage of delta sleep, and percentage REM sleep. Simple slopes analyses indicated that PM exercise was unrelated to changes in sleep maintenance and percentage of delta sleep, whereas the other conditions were linked to reductions in sleep maintenance over time, in addition to increases in percentage of delta sleep. PM exercise condition predicted significant increases in sleep latency over time. Both exercise conditions elevated percentage REM sleep. Note. Mag = Magazine Control Condition; AM Ex = AM Exercise; PM Ex = PM Exercise.