My son was diagnosed with Type 1 on the 14th November a couple of weeks before his tenth birthday. We're still in the honeymoon phase and we've been getting good control with 90% of his readings between 4-9 using a four-injections-a-day insulin routine and carb counting at meals - keeping most meals to 75g carbs. Before his diagnosis my son would play rugby for a local club but he's been nervous about going back- because he thinks he's unfit now and because he's scared of what rugby will do to his blood sugars. So I thought I'd encourage him to come with me for a gentle run while we're on holiday to work out how to do the balancing. On Monday I took him out - and being an energetic ten year old, he went faster and further than I expected and got ahead of me and demanded to go the long way. We ran 4.3 km in 35 minutes. Yesterday we did a second run and he wasn't feeling quite as energetic and we did 2.7 km in 20 minutes. The problem is one run led to a hypo and the next we overcompensated and he went hyper. Both mornings we gave him half a unit less novorapid for breakfast. On Monday he had a small fruit juice before running and a 15g carbs cereal bar after running. Yesterday he drank 200ml ribena before and during running (no cereal bar after). Both days had similar normal readings before lunch and we dosed normally for lunch. Both days he was a bit high before the evening meal (around 10). On Monday we dosed normally for the evening meal and two hours later he was hypo with a BG of 2.9 (and we treated with glucose). Yesterday we gave him half a unit less for the evening meal and two hours later he was hyper at 15.8 (and we treated with a 1 unit correction shot). So what do we try next? The ribena was a temporary sports drink option, I have now got a proper sports drink. I'm thinking that maybe if he drinks that during running he doesn't need to cut the later Insulin dose? Or perhaps I shouldn't have given him so much to drink during the run? What experience do others have?