The study authors say the findings suggest a “one-size fits-all” approach to exercise timing is less than ideal.
A mismatch between biological and social schedules or “social jetlag” has been linked to increased heart risk.
Night owls can be at greater risk of this, they add, meaning they shouldn’t force early morning exercise routines.
Some gyms now stay open all hours, night and day.
Hugh Hanley, head of personal training at PureGym, says Monday and Tuesday evenings are typical peak busy times but, increasingly, people are spreading out the hours they train.
“One thing we have noticed over the last few years is people are actually prioritising their health more, bringing in more flexibility.”
He says the key to staying fit is consistency – creating a habit of movement, building it into your lifestyle.
“Doing it regularly is better than one or two blasts.
“We see a lot of the time that people set too big a goal initially. We’d always rather they break it into small bite-sized goals that are achievable.”
The trend at the moment, he says, is strength training. “We’re seeing a big rise… across all generations. The younger generation are definitely prioritising strength training, but even the older demographic.”