I knew that diabetics can suffer from hypo attacks during exercise but I didn't know hypo attacks could follow many hours afterwards : "General sports nutrition recovery strategies are the same as for non-diabetic athletes. Fuel and fluid used during exercise needs to be replaced. The increased insulin sensitivity caused by exercise lasts for several hours after exercise. Therefore the risk of hypoglycaemia persists for some time. Delayed hypoglycaemia can occur 4-48 hours after exercise. Preventing delayed hypoglycaemia involves making sure you consume sufficient carbohydrate before, during and after exercise. It may also be necessary to reduce the next insulin dose after exercise. It is helpful to monitor your blood glucose levels frequently after exercise. Inconveniently, delayed hypoglycaemia often occurs during the night. If this occurs regularly, it can exacerbate fatigue in athletes. Waking up feeling very tired and groggy in the morning may indicate you have experienced a 'hypo' during the night. This is a sign that you need to increase blood glucose monitoring after similar exercise sessions in the future." http://www.ausport.gov.au/ais/nutrition/factsheets/special_diets/diabetes_and_sports_nutrition Interesting? The source is the Australian agency for high performance sports so should be fairly reliable. I'd still like to see the scientific sources though.