Is there a perfect time to work out? Science seems to think so

When it comes to exercise, are you a morning person? - Westend61/ Getty
When it comes to exercise, are you a morning person? - Westend61/ Getty

What time do you usually work out? Now that we’ve all spent almost a year in our trousers-optional new reality, your answer might equally well be “first thing in the morning,” “straight after my 11am work call,” or “whenever I need to work off some stress about the new hellworld we all live in” – but is there actually a correct answer?

Some new evidence suggests that there is. A Spanish study published in 2020, for instance, found a correlation between exercising between 8am and 10am and a reduction in the risk of certain types of cancer, leading the study authors to suggest that the beneficial effects of early exercise for breast cancer risk may have links to oestrogen or melatonin production (prostate cancer also saw a reduction in risk, though a less statistically significant one). Then again, the differences between the case study group and controls were small and could be correlation; for example because people who make time for exercise early in the day are also likely to engage in other healthy behaviours. So is there anything else you should bear in mind?

Well, another consideration is when exactly you’ll feel best. In one study, published in the Journal of Sports Science, researchers found that test subjects were able to work harder in the evening so there’s a chance that, even if it feels like you’re training hard when you crank up the Rocky playlist first thing in the morning, you’re not actually putting forth your best effort.

World records are often set in the afternoon and many serious athletes leave their workouts until the mid-morning, based on the fact that a whole host of biological processes take a while to get online. Other studies suggest that the afternoon and evening are when your reaction time is at its quickest, which might be important for HIIT workouts, speed training or skill-based workouts.

What about the morning? Some trainers suggest that fasted workouts are better if your goal is fat loss, suggesting that early AM might be best if you’re looking to shed some lockdown pounds, but there’s little scientific evidence to back up that speculation. More promising is that you might actually be more able to stick to an omelette instead of going on a toast bender after a big workout. Research from Brigham Young University suggests that 45 minutes of moderate-to-vigorous exercise in the morning is more likely to reduce your appetite than build it up. A much shorter workout can also set you up for the day – researchers at the University of Georgia found that sedentary, otherwise healthy adults who engaged in as little as 20 minutes of low-to-moderate aerobic exercise, three days a week for six consecutive weeks, reported an increase in energy levels and feeling less fatigued.

A general rule of thumb, then, might be if you’re aiming to actually get better at working out – shifting more weight, running faster or leaping taller tree trunks in a single bound – it makes more sense to save it for lunchtime or the afternoon. If you’re looking to make positive changes in the rest of your life – by feeling less stressed, more productive, or shifting some weight – earlier in the day is probably fine and might be beneficial.

The real truth, of course, is that the best workout is the one you’ll stick at regularly – not the one that’s scientifically advisable but you’ll always skip. Really, it’s fine to snatch a workout at any time of day: first thing in the morning if you’re keen, a couple of hours before bed if you can’t fit it in any other time, or 10 minutes before lunch if you’re feeling guilty about the Deliveroo you’ve just ordered and the driver’s on his way.

One caveat: if you’re aiming to build a habit, it helps to choose a timeslot that you’ve at least got a fighting chance of sticking to every day: if you’re consistently too worn out from a day of doomscrolling or home schooling to actually work out at 6pm, consider when in your day the prospects might be better. And if your answer to the question at the top was “Er, I don’t” – then start today, even if it’s just for a couple of minutes. Any time is better than never and any amount is better than none at all.

Do you have a preferred time of day for working out? Let us know in the comments section below.