This makes me a more versatile teacher and I feel prepared to design effective workouts for a wide variety of clients and body types. (merrithew.com)
They are short and provide the most effective workouts in the least amount of time. (robinskey.com)
The idea behind it is you can get a similarly effective workout in only 4 minutes as compared to 60 minutes of steady - state cardio. (coachcalorie.com)