Evening exercise does not appear to disrupt sleep or alter energy intake.  

Exercise

Just about anyone who has trouble sleeping has filled out a sleep hygiene questionnaire and received education to avoid exercise within 4 hours of bedtime because it will disrupt sleep and make you hungrier.  In today’s culture, following this advice makes evening exercise nearly impossible.  If you are like me, you are lucky to be home by 5:30 p.m.  Once you make dinner and clean the dishes, it is 7 p.m.  It is just too late to exercise without disrupting my sleep or is it.  Unfortunately, medical provider continue gives this advice despite a lacking in evidence to back the belief that exercise interferes with sleep and increases appetite.

A recent study looked at these sleep and energy intake in men who performed high‐intensity interval exercise within 4-hours of bedtime[1].   The researchers sought to show high-intensity training could be completed in the early evening without subsequent sleep disruptions and may reduce appetite‐related hormone concentrations.  In the study, eleven inactive men undertook sleep monitoring to determine baseline sleep stages and exclude sleep disorders.  

On separate days, participants completed 30 min of high-intensity exercise in the morning, afternoon, and early evening.  Researchers measured appetite‐related hormones and glucose.  They also performed overnight polysomnography and collected self‐reported sleep and food diaries for 48 h post‐exercise.  

The researchers found that there were no between‐trial differences for total sleep time between the three exercise times.  At 30 min post‐exercise, ghrelin was higher for afternoon exercise group when compared to morning and evening. Glucose was higher for morning exercise group when compared to afternoon and evening.  There was no difference in perceived hunger or energy intake between the groups.  

The bottom line:  There is no medical or research back rationale to recommend that we should avoid exercise in the early evening.  Although this study was done in men who performed a high-intensity workout, there is no reason to believe that it is limited to one gender or exercise type.  Personal experience may find that it may affect your sleep, but the research indicates that it should not affect your rest or energy intake.   Exercise is good your health and waistline so exercise away.