Arnold Schwarzenegger Warns: Late-Night Workouts Could Be Hurting Your Sleep
Arnold Schwarzenegger is sharing a clear message for people who like to work out late at night. His advice is simple. Hard workouts too close to bedtime can hurt your sleep and slow down recovery.
The bodybuilding icon and movie star talked about this in his newsletter, Arnold’s Pump Club. He explained that heavy training in the late evening can keep the body too active when it should be calming down.
According to him, this makes it harder to fall asleep and get deep rest.
Schwarzenegger pointed to scientific research to support his warning. He wrote that studies show intense exercise done within four hours of bedtime can delay sleep and shorten it. He said, “Scientists found that intense workouts four hours before bed can push sleep later, cut sleep time, and stress the nervous system, while light or moderate exercise at night is usually fine.”
He referenced a study from Monash University that was published in Nature Communications. The research looked at data from more than 14,000 active adults. It tracked when they exercised, how hard they trained, and how that affected sleep length, resting heart rate, and heart rate variability. The results showed that very hard workouts late at night kept the body in a high-alert state when it should be resting.
The study found that people who finished very intense workouts close to bedtime fell asleep much later. In some cases, sleep was delayed by over an hour. Schwarzenegger summed up the findings clearly, saying it led to “80 minutes later sleep, 43 minutes less sleep, and a 33 percent drop in heart rate variability.”
He also shared one key detail. If intense training ended at least four hours before bedtime, these negative effects were not seen.
Still, Schwarzenegger knows that many people have busy lives. Not everyone can train earlier in the day. For those people, he says there is no need to panic.
“If evening is your only time to train, don’t worry. Just be smart about it,” he wrote. He suggests saving the hardest workouts for earlier hours when possible. At night, lighter sessions or shorter workouts are a better choice.
He also reminded readers how important sleep is for building muscle and staying strong. Schwarzenegger often repeats a rule he has lived by for decades. “You grow when you sleep, not when you train.” During sleep, the body releases growth hormone, which helps repair muscles and restore energy. Poor sleep can slow progress, weaken recovery, and affect overall health.
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