Though interval workouts sound daunting, anyone can do them, says Phil Campbell, the creator of the Sprint 8 interval program. "You don't have to run full speed," he says. "You don't even need to run. You can bike, swim, elliptical train, even power walk." What's important is that during the interval, you push yourself hard enough that you can't maintain the effort longer than 30 seconds.
How It Works
Warm up for two to three minutes. Start your first 30-second interval. If you don't want to run, simply increase the incline on the treadmill 3 to 6 percent and speed up enough to feel that you're working hard. Let the 1-to-10 exertion scale (10 being all-out) be your guide. The effort should feel like an 8 (for the first few sprints) to 10 (for the final ones). After 30 seconds, recover at a casual walking pace for one and a half to two minutes, and then do it again for a total of eight intervals. Wrap up with a two- to three-minute cooldown. The workout will take 20 to 25 minutes.
- Your body needs time to adapt to the rigors of intervals. If you've been very sedentary, ease into the intensity by brisk-walking the intervals to start. For those unused to a fast pace, do just two moderate sprints the first time.
- Allow a day of rest between interval workouts to give your body time off to recover and rebuild.
- As with any exercise program, see your doctor before starting.
Because even the shortest workouts can become a bore, you'll appreciate how easy it is to vary intervals. These two suggestions are each less than 25 minutes including warm-up and cooldown. Again, base your intensity on a 1-to-10 scale, with 10 being tail-on-fire intense.
- Three minutes: Warm up at an easy (3) to moderate pace (6).
- Three minutes: Boost intensity (7).
- Two minutes: Push a little harder (8).
- One minute: Keep increasing your effort, and finish the last ten to 15 seconds as hard as you can go (10).
- Six minutes: Recover (4 to 5).
- Repeat the three-two-one interval.
- Two minutes: Cool down (4).
- Five minutes: Warm up at an easy to moderate effort (5 to 6).
- Two minutes: Increase your intensity to just shy of full-on effort (9).
- Two minutes: Recover (5 to 6).
- Repeat the on-off interval four times.
- Three minutes: Cool down (4).