Arnold Schwarzenegger believes workout timing can significantly affect gains. In a recent Arnold’s Pump Club Newsletter on Dec. 1, 2025, he revealed that evening training can sabotage sleep quality and recovery.
It’s been nearly 50 years since Schwarzenegger’s seventh and final Mr. Olympia victory. Life beyond the stage looks different compared to the prime years of his career. While he still structures workouts around muscle building, longevity, mobility, and wellness have taken priority.
Schwarzenegger has faced health setbacks throughout his life, including heart problems. Last year, he had a pacemaker installed; it was a wake-up call that nudged him to look after his health even more at 78 years old.
Arnold Schwarzenegger Discusses How Evening Workouts Affect Sleep and Recovery
In his newsletter, Schwarzenegger took a close look at how exercising at night can affect sleep quality. He notes that it’s not just about when you train, as effort also plays a factor.
“Do Evening Workouts Steal Your Sleep?
If you’ve ever crushed a late workout only to lie in bed staring at the ceiling, you’re not imagining things.A new study took a deeper look at how evening exercise affects your sleep, and the real answer isn’t just about when you train but about how hard you push.”
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He pointed out that hard workouts can delay or shorten sleep.
“Scientists found that hard workouts within 4 hours of bedtime can delay sleep, shorten sleep, and stress your nervous system, but light or moderate evening sessions are usually fine.
Nearly 15,000 active adults wore WHOOP devices for an entire year, generating more than 4 million nights of sleep data. They measured training intensity (what the study calls “strain”) and timing influenced sleep onset, sleep duration, resting heart rate, and heart rate variability (your recovery signal).”
He reported that even completing an intense workout two hours before bed can significantly impact sleep and, consequently, recovery.
“When intense workouts ended 2 hours before bed, people fell asleep 36 minutes later, slept 22 minutes less, had a higher heart rate overnight, and saw HRV drop 14% — all signs their body wasn’t ready to recover.”
If you finish that same hard workout after your usual bedtime, and things got dramatic: an 80-minute delay in sleep onset, 43 minutes lost in sleep, and HRV down 33%.
Schwarzenegger added that lighter sessions performed at least four hours before bed had less of an impact on sleep and recovery.
“But if you finished training at least 4 hours before bed, even intense workouts had no negative effects. And within that 4-hour window, lighter or shorter sessions were far easier on sleep and recovery.
The scientists believe high-strain exercise keeps your body in “fight mode” longer, which means an elevated core temperature, higher heart rate, and a nervous system that hasn’t shifted back to calm.”
For those who can only train in the evening, Schwarzenegger said it’s best to be strategic. That could mean sticking with lighter or moderate workouts closer to bedtime.
“If evening is your only time to train, don’t stress — just be strategic. If possible, schedule your hardest workouts for earlier in the day. Or, emphasize lighter or moderate workouts for later at night. And if that’s not possible, emphasize other techniques that help you wind down at night to improve your sleep. (See the following item.)
Minor adjustments can protect your sleep, your recovery, and how good you feel tomorrow without giving up your evening routine.”
Although there seems to be some clear risk factors to training later at night, some legends of the sport proved that it could be a winning strategy. Former eight-time Mr. Olympia Ronnie Coleman and four-time titleholder Jay Cutler both admitted to training at night. They remain two of the greatest Mr. Olympia champions the sport has seen.
Depending on effort, Schwarzenegger believes it’s possible to work out later at night without significant repercussions. However, he emphasized that those training with intensity in the evening could risk compromising sleep and recovery.
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