Try This Workout

This can be done on any cardio machine with a built-in heart rate monitor. Or do it outside — walking, running, or biking — if you have a tracking device. • 5 minutes in Zone 1. • 10 minutes in Zone 2. • 3 sets of 1 minute mid Zone 2, 1 minute high Zone 2, 1 minute Zone 3. • 2-5 minutes mid Zone 2. • 5 sets of 30 seconds Zone 4 followed by 30 seconds Zone 3. • 5 minutes Zone 2. • Optional: 1 minute Zone 4. • 2 minutes Zone 2. • 5 minutes low Zone 2 and Zone 1.