As i started to play tennis more competitively i started to run more on the treadmill. I used to run a few miles on it every day. All of a sudden i noticed a slight pain in my shins when i ran. I was stupid and carried on running every day and now i cannot run more than 500 meters on the treadmill. I dont know if this is definitely shin splints or not, but its painful. The only time it doesnt hurt is when im actually playing tennis, but i know that to keep my endurance up i need to train off court as well. Will regular workouts on an exercise bike be good for m endurance? especially as it would be better on the shins and joints. Would very fast walking on the treadmill still help me a lot? I've tried it and it is a lot less painful. Could anyone recommend any other ways of keeping fit apart from distance running?