Hi JulieannC! I personally do not like to advocate more than two extremely intense interval workouts per week. They are very demanding on the joints and require at least a few days rest between the workouts. But over the years I have realized that some people simply enjoy the concept of doing intervals (pushing hard and than recovering) for their workout format but they do not push to the extreme. If this is your case than yes, doing three a week with a days rest in between should be fine. Keep safe and cut back on the frequency of these workouts if you start experiencing quirky pains here and there. Good Luck!