When i bicycle at high intensity for a long time (50+ miles) i suffer from restless leg syndrome when i try to fall asleep. is this normal?

Post Exercise: It sure sounds like you are not giving your muscles time to recover after such a long and vigorous workout.. This means hydration with the appropriate electrolytes, winding down with post exercise slow cycling, walking (just like one warms up one should warm down; and the slow post exercise stretching!

Normal : This occurs if one gets dehydrated with electrolyte imbalance, lack of warm up and doing too much exercise too quickly .