This study, as shared by Medical News Today, focused on times of day and not types of exercise, eliminating variables such as exercise equipment mistakes or different diets. The 56 participants aged 25 to 55 took part in a 12-week program. One interesting insight was shared by Dr. Asad R. Siddiqi, assistant professor of physical medicine and rehabilitation at Weill Cornell Medicine in New York City. “The men studied had greater improvement in perceived mood state than women. The exercise seemed to decrease tension, depression, anger, substantially in men regardless of the time of day, whereas improvements in tension and depression were only seen in women who exercised at night.”

Improvements in the men studied were “less pronounced” than in the women, but exercising at all showed improvements in the men’s physical performance. Exercising in the evening, however, added “benefits in heart and metabolic health, as well as lower fatigue.”

Posits Dr. Arciero, “The precise mechanism, is not clear, but may be related to neuro-hormonal-psychological effects of exercising later in the day as a form of a ‘stress-reliever’ that may also favorably impact sleep quality. It’s interesting to note that [p.m.] exercise in men also significantly reduced feelings of fatigue.”

https://www.thelist.com/897380/the-results-of-a-new-study-on-womens-exercise-routines-might-surprise-you/