Warm up before you exercise

My right hand is in pain again. Due to repetitive stress i put on it for playing tennis on the Wii. Guess my warm-up session wasnt long enough. Or maybe i played for too long. Take it as lesson learnt. Whether one is playing sports games on the Wii, or working out on treadmills at the gym. Do remember to warm up beforehand. If not, you'll only end up with sore muscles like i am now. I think i need another week's rest before i can play Tennis on the Wii.