My 12 year old son plays a lot of sports and often has a red or blue sports drink to rehydrate. He seems to wet more often on the nights he has a sports practice or game? Is there a correlation?
There may be several factors at play here. The extra sugar and tasty flavor may encourage him to drink more than he would if it was plain water. In some children, the red and blue coloring agents cause the bladder to be more irritable and need to empty more urgently or frequently. Also, chances are that his body is more fatigued on the nights that he has sports activities. It may be more difficult for him to spontaneously wake up when he needs to go to the bathroom.
Sports are important and your son will eventually learn to stay dry every night, in spite of his evening activities or fluid intake. Until that time comes, rehydrating with water or a clear sports drink is preferable. Drinking before the practice or game will allow his body to process the fluids as the evening progresses. If he feels thirsty, allow him to drink after his practices. Encourage him to void twice before bed, about 20-30 minutes apart, so that he starts the night off with a completely empty bladder. Being well rested is also helpful. Having his homework done earlier in the evening should allow him to have a regular bedtime.