Experts reveal if there really is a ‘best’ time to work out, and their answers might surprise you.

The best time to work out has been discussed, debated, and disputed for years in the health and fitness industry. Should you train in the morning or in the evening? It’s still the question on everyone’s lips.

Research – like this study published by Cold Spring Harbor Perspectives in Medicine (opens in new tab) – shows us that the benefits of exercise continue to stack up, like improved weight loss, torching calories (opens in new tab), increasing bone density (opens in new tab) and muscle mass, and kicking up your cardio fitness. Exercise can even reduce stress levels and improve your sleep, but if you’re training towards specific goals, experts believe that timing really could matter.

It’s tough enough shoehorning workouts into your busy schedule, let alone timing them to suit your fitness goals. But if you want to maximize your results, you might want to rain check certain times of day to do so, and there could be some weight in optimizing your training schedule.

We thought it was time to set the record straight. Find the best fitness trackers to monitor your training, or read on to see what trusted experts said when we asked – is there a ‘best’ time to work out? And why does it matter?

Morning exercise benefits

Is it better to work out first thing in the morning? “It’s a good question. And like most things, there is no template answer as there are so many factors to consider,” Gary Brickley, (opens in new tab) senior lecturer at the School of Sport and Health Sciences at the University of Brighton, tells Live Science.

One reason we might choose to work out in the morning is because it’s when we feel most alert. This is important from a neuromuscular point of view, Brickley explains, as being alert could help us master new sporting skills. But if you’ve slept poorly and are suffering with fatigue, then working out first thing will mean that you struggle to focus.

However, exercising first thing in the morning could be beneficial in other ways. If you work out before you eat, then your body won’t be able to draw its energy from recently consumed food – so it will start targeting stored fat instead.

“The work by researchers Atkinson and Reilly (1996) (opens in new tab) also suggests that exercise timing should be phased around our hormonal status,” Brickley says. “Cortisol (our stress hormone) and testosterone (opens in new tab) may peak in the morning, and this is when glucose might drop and insulin increases, which may be favorable for improving fat metabolism in an overnight fasted state.”

Brickley suggests endurance athletes could utilize the morning for their longer, steadier aerobic exercise (opens in new tab) sessions to encourage fat metabolism.

Afternoon and evening exercise benefits

So, if morning exercise is better suited to endurance and fat burn, is there a place for afternoon or evening exercise?

Some recent research points to training in the evening as best for muscle mass growth. In a study published in Applied Physiology, Nutrition, and Metabolism (opens in new tab), the effects of a 24-week training program performed in the morning versus evening showed a notable gain in muscle mass for evening training, especially when combined with endurance training.

However, late night workouts could impact the quality of your sleep. A study published in the Journal of Health Psychology (opens in new tab) shows delays in sleep for evening exercisers versus morning exercisers.

Brickley agrees, but points out that exercise in general should improve sleep quality. “A study by Kovacevic et al (2021) (opens in new tab)showed an improvement in sleep quality after resistance exercise. But, in other people, they may be hyperalert after training and could struggle to sleep following intense exercise.”

Sleep should never be compromised if you want to maximize results. Lindsay Browning (opens in new tab), psychologist, neuroscientist, and sleep expert, says that intense exercise too close to bed could disrupt your sleep because of the release of endorphins and adrenaline that make you feel more alert. But in general, exercise is good for our sleep.

“As well as being essential for overall health, moderate exercise has shown to increase deep sleep during the night, which helps you to wake up the next day feeling more refreshed,” she explains. “The more you exercise, the more deep sleep you’ll have. This is important because deep sleep is the part of our sleep cycle where our body physically repairs and regenerates.”

There also seems to be early evidence that afternoon exercise could benefit anyone who is metabolically compromised or has type II diabetes. A small study published by The Physiological Society (opens in new tab) found superior metabolic effects in afternoon exercisers (between 3-6:00 pm) versus early birds. Later day training even triggered better exercise capacity and decreased body fat content.

The bottom line

So, is there an optimal time to train? While early bird training appears favorable for fat loss, intense resistance-based training seems better suited later in the day, when athletes are adequately fuelled and fired up. A study published in Scientific Reports (opens in new tab)also supports training later in the day for short-duration maximal exercise, like sprinting or jumping.

Rami Hashish (opens in new tab), Ph.D., DPT, body performance and injury expert, summarizes to Live Science, “It certainly seems working out in the morning trumps exercising in the afternoon or evening. Not only because it helps boost your metabolism as you start your day, but also because working out on an empty stomach is associated with greater fat burn.” He says. “Working out in the morning is associated with an overall increase in activity level throughout the day and a potentially reduced likelihood of indulging in unhealthy foods.”

On the flip side, your body temperature is lower as soon as you wake up, so you may need more time to warm up. “Because of this, you may perform better later in the day when your muscles exhibit greater force, power, and performance,” Hashish concludes.

So, like many things, there’s not one single correct answer. If you’re looking to optimize weight loss and fat burn, it appears working out in the morning is the way to go. But, if you’re looking to maximize your performance and hit some personal bests, you may want to wait until later in the day.

What other factors affect exercise performance?

There are periods where people naturally feel and work better, which may be conditioned socially or otherwise. “Thankfully there is no ‘golden time’ for training,” Brinkley tells us. “Otherwise gyms, pitches, and swimming pools would be fully booked [at certain times of day]. Training needs to be programmed around sleep, hormonal responses, recovery, what response is required from training, nutrition, and availability.”

A review article posted in the Journal of Dental and Medical Sciences assessed the outcomes of multiple studies across different types of exercise performed at different times of the day. Their discussion concluded there are significant pros and cons for both times of day, and suggested the main consideration should be to opt for consistency with whatever you choose, allowing yourself to be flexible.