While of course exercise has great benefits whenever you choose to do it, it seems the time of day you go for can affect your goals differently, according to new research.
For example, women who want to lose weight should exercise in the morning, while those who want to build muscle should work out in the evening, the US study suggests.
It also unearths the best time of day to exercise may be different for men and women – women burned more body fat during morning exercise, while men saw more benefits from evening exercise.
While the exact reasons for the findings are unclear, authors from the study suggest it could be partly due to differences in hormones, biological clocks and circadian rhythms (sleep-wake cycles).
The researchers also suggest women may burn more body fat in the morning because they are more likely to have excess belly fat.
It should be noted that all participants who took part in and stuck to the study improved their overall health and performance during the trial, regardless of when they exercised.
"The best time for exercise is the best time you can do it and fit it into your schedule," Dr Paul Arciero, lead study author and professor of health and human physiological sciences at Skidmore College, New York state, told the BBC.
However, he suggested there is "something else going on", which may mean the ideal time of day to exercise varies depending on what you want to achieve, and differs for men and women.
Women wanting to reduce fat around their middle and reduce blood pressure should aim to exercise in the morning, Dr Arciero explained in more detail. Losing tummy fat is important because it can surround the body's internal organs, like the liver, which can be dangerous.
However, for women wanting to improve muscle strength in their upper body, as well as their overall mood and food intake, they should exercise in the evening, he added.
While the men in the trial were less affected by the time they worked out, with their strength improving in both mornings and evenings, the latter was found to be "ideal for men interested in improving heart and metabolic health, as well as emotional wellbeing".
Losing weight, exercising regularly, eating a healthy and balanced diet, stopping smoking and cutting down on alcohol can all help prevent or reverse 'metabolic syndrome'.
This is the medical term for a combination of diabetes, high blood pressure (hypertension) and obesity, which can put you at greater risk of getting coronary heart disease, stroke and other conditions that affect the blood vessels, according to the NHS.
Some 30 women and 26 men – all nonsmokers, healthy and between 25-55 years old – underwent a supervised programme of exercise for 12 weeks. This included a mix of stretching, sprint, resistance and endurance training.
They were assigned either early morning sessions (between 6.30-8.30am) or evening sessions (6-8pm), completing a different routine each day, for four days a week, all of which lasted less than an hour except for endurance, which was performed for an hour or longer.
Men and women in both groups were provided with meal plans designed by dieticians.
Researchers tested everyone's blood pressure and body fat throughout the study, along with their flexibility, strength and aerobic power, observing any changes.
Read more: The NHS' 12-week weight loss plan explained
Watch: Five tips for getting back into exercise
The study – published in Frontiers in Physiology – tracked people with a healthy weight, but researchers also say the programme could be beneficial on people who are overweight or obese. "They have more to benefit", said Dr Arciero.
While the research was relatively small, as most studies in this field have so so far been based on just men, the findings are still significant – though more needs to be done to understand the differences between the sexes better.