I don't think your cleanses were too close together. 3 months is plenty of time.
Exercise and the Master-Cleanse work together, but you really need to listen to your body. Some people need to cut back on the stenuous exercise, or the length of time they can exercise. Some of us take a spoonful of blackstrap molasses just before and/or after exercising. My recommendation: start out slow and see what your body is capable of. That may change from day to day.