What are the best exercises for a breastfeeding mother?

Exercise is good. Make sure to stay hydrated. The baby may prefer to nurse prior to exercise. Baby may also not like to nurse after you have been sweating, so wash the breast.
Every kind. With the addition of a good supportive bra, all types of exercise are good for a breastfeeding mother, from walking to aerobics to yoga or tai chi. Good hydration is important during and after exercise, too.