Ideal time of day to exercise differs between active men and women

Exercise has physical and mental health benefits whatever time of day you manage to fit in a workout, but the ideal time of day to maximise on fitness gains may be different for men and women, according to a recent US study. 

Not all of us have scope to shift our routines, but if you do have the choice of jumping on the turbo or heading outside for a ride, before or after work, researchers have found that there are differences in men’s and women’s response to morning and evening exercise.

Many research papers in exercise science, includings ones on this area, have predominantly focused on men. The reason for this is generally put down to the ‘complications’ of women’s hormonal fluctuations throughout the menstrual cycle – but the result is a gender data gap that leaves us in the dark about one half of humanity.

Because gender does make a difference, affecting carbohydrate metabolism, blood plasma levels and body temperature regulation – as well as inflammation and incidence of injury. Now researchers have found that the best time of day to train does differ between men and women.

Based on the results of the study, researchers say that early morning exercise could benefit physically active women who are aiming to reduce body fat and blood pressure, whereas men burn more body fat in the evenings. 

The 30 men and 26 women participating in the study were aged between 25 and 55 years old and consisted of those defined as ‘highly active’ (completing more than 30 mins of structured physical activity 4 days a week for more than 3 years). They were lean with a BMI <25 kg/m2 and % body fat <30%. 

The study lasted 12 weeks and researchers analysed the effects of a varied training programme - consisting of stretching, resistance exercise, interval sprints and endurance training - with the same relative training volume.

Participants undertook one of the four different exercise routines one day per week for a total of four training workouts per week.

One group exercised for an hour before 08:30 while the other group followed the same exercise routines, but in the evening between 18:00 and 20:00.

“Morning exercise in women enhances total and abdominal fat loss, reduces blood pressure, and increases lower body muscle power,” the study concluded, while “evening exercise greatly increases upper body muscle strength, power, and endurance, and enhances overall mood.”

It was found that men improved their strength in both morning and evening exercise, but experienced additional benefits during evening exercise, with “lower systolic blood pressure and fatigue, and stimulates fat oxidation compared to early morning exercise.”

Researchers say more research is needed to find out what factors are responsible for the variation in men’s and women’s responses to the time of exercise. 

Also it’s worth being aware that the study focused on men and women who are already physically active and so more research needs to be done to find out if the same patterns emerge for those who are overweight or obese.