Arnold Schwarzenegger says exercising at night does not lead to greater fat loss, despite recent research suggesting potential health benefits. The Terminator actor, who launched his newsletter, Arnold’s Pump Club, in 2023, attracted tens of thousands of subscribers who receive daily fitness, nutrition, and wellness tips from the former bodybuilding star and his team. And one of the things he addressed was the claims that working out later in the day can boost fat burning.
The former Governor of California acknowledged that some studies have found correlations between evening exercise and improved health outcomes, but stressed that the overall body of research does not support the idea that workout timing affects fat loss.
In a recent edition of his Arnold’s Pump Club newsletter, Schwarzenegger wrote: “Does the timing of your workout affect how much fat you burn and the results you get? A recent study suggested that overweight or obese people who do more rigorous activity between 6 pm and midnight had a lower risk of premature death and cardiovascular disease.”
He cautioned, however, that the study was observational and did not establish cause and effect. “Does this mean exercise is more effective at night? Not exactly,” he said, explaining that the research did not prove the timing of exercise was responsible for the results. Schwarzenegger added that while such data can still be valuable, it must be interpreted carefully: “The research was an observational study. That doesn’t mean the data is worthless (it leads to many more great questions and studies), but we have to be careful not to overstate what was tested and compare it with other, more detailed studies.”
Schwarzenegger also pointed out that researchers analyzed activity tracker data from about 30,000 people, but did not measure structured workouts. As he explained, “The scientists took data from a pool of 30,000 people who wore activity trackers. That was great, but the problem, as the study’s lead scientist pointed out, was that they didn’t measure or track structured exercise.”
He then pointed to a more rigorous trial that found no difference in fat loss between workout timing conditions. “Just last year, a randomized controlled trial (the gold standard for research) examined 100 overweight people, had them all perform the same workout, and then determined if training in the morning or night made a difference,” Schwarzenegger said. “The scientists found that the timing of exercise did not influence fat loss.”
Schwarzenegger emphasized consistency as the key factor in weight loss, concluding that it matters far more than whether someone works out in the morning or evening. “For now, your best advice comes from a recent meta-analysis that found exercise consistency matters much more than the time you work out,” he said, before adding a final message for readers: “Just train. That’s all I ask.”