Something like this could be several things. To much sugar before bed. Not enough physcial activity during the day. Is he going to be to early? Sleeping heavy for a few hours and then up and down all night? Is it stomach problems? Bathroom troubles? You need to make a list of possibilities and check them off......good luck.
Agree with the above. Would like to add restless leg syndrome. You may want to give him a melatonin before bed to help him sleep. Melatonin is a chemical produced by the brain to aid in sleeping. Some don't produce enough. You can buy it in any pharmacy.
Also remove all caffeine and artificial colors & flavors from his diet.