Resistance exercise 'activity breaks' at night may improve sleep length, suggest the findings of a small comparative study published in the open access journal BMJ Open Sport & Exercise Medicine. Three-minute breaks every 30 minutes over a period of 4 hours may be all that's needed, the findings indicate. Current recommendations discourage intense exercise before going to bed, on the grounds that it increases body temperature and heart rate, which can result in poorer sleep quality, say the researchers.
While activity breaks can improve metabolism after a meal, it's not clear if they have any impact on sleep. Poor sleep is associated with an increased risk of cardiometabolic disorders, such as coronary heart disease and type 2 diabetes, explain the researchers. To explore this further, the researchers recruited 30 non-smokers, aged 18 to 40, to their study.
All of them reported clocking up more than 5 hours of sedentary time during the day at work and 2 hours in the evening. To capture habitual physical activity and sleep patterns, participants wore an activity tracker worn continuously on their non-dominant wrist for 7 consecutive days. And they were asked to record the periods they didn't wear it, the time they went to bed, and when they woke up.
They were also asked to record any physical activity when not wearing the activity tracker, such as swimming or contact sport, and to record activities known to be inaccurately identified by the tracker, such as stationary cycling .
