Interval Cardio

Interval workouts include bursts of maximum effort grouped with lower and medium effort.

Cardio intervals are perfect if you're short on time but still want great results. The best part: You can do it with any type of cardio—running, elliptical machine, cycling, even walking—so there's no excuse to skip a session.

Base your intensity on your rate of perceived exertion (RPE), or how hard you feel like you're working (at 1, you can chat; at 10, you're unable to speak). Keep in mind your RPE will change as your fitness level improves.

Time                 Intensity                    Effort (out of 10)

2 minutes          Easy-Moderate          4

2 minutes          Moderate                   5

1 minute            Hard                          8

2 minutes          Easy-Moderate          4

2 minutes          Moderate                   6

1 minute            Hard                          8

3 minutes          Easy-Moderate          4 

2 minutes          Moderate                   6

1 minute            Hard                          8

4 minutes          Easy                          3