Q I run about three times a week for half an hour in the early evening. After running, I fall asleep easily but wake after a few hours and struggle to get back to sleep. Is this a delayed endorphine buzz?
A The causes of insomnia are still widely unknown though many theories have been suggested. Among the more popular theories for the symptoms you describe is that the increase in body metabolism and body temperature due to running interferes with your sleep. Your body rests better when it is slightly cool and it may be that your body temperature is not dropping after exercise, making it harder for you to stay asleep.
It is likely your disturbed sleep is down to running in the evening. Many researchers say that if you have problems with insomnia you should avoid running within six hours of sleep. One suggestion to get around this would be waking 30 minutes earlier in the morning to run, or running to work or at lunch time.
If running in the evening is your only option, it is worth trying relaxation methods, such as yoga or stretching, before going to bed. Try a class or a video. Yoga and stretches have the added advantage of improving flexibility and strength, which will help your running.
—Jane Newman, sports physiotherapist and ultra runner