Engaging in moderate physical activity including walking cycling or jogging in the evening does not cause sleep problems suggest researchers. The research challenges previous studies that suggested that sleep quality can be improved by avoiding exercise in the evening. The findings showed that doing exercise for four hours before going to bed does not have a negative effect on sleep. However vigorous training within an hour before bedtime may have a negative effect on sleep. If doing sport in the evening has any effect on sleep quality at all it is rather a positive effect albeit only a mild one