The workout du jour is high-intensity interval training, and this is one format that might be here to stay. It requires only a few minutes of (really) hard work to cover all the major muscle groups. HIIT, as it’s called, alternates short periods of all-out activity with even briefer breaks. Just how short is short? Typically 20 to 30 seconds of work followed by 10 seconds of recovery – spiking metabolism and tricking your body into thinking it rested.
Although a four-minute workout is better than a no-minute workout, there’s a kicker. To get the most out of HIIT, you should incorporate it into your longer sweat sessions. Think sprints in spin class or a high-octane circuit drill.Several apps can help rev up your reps. Quick 4 Minute Workout’s (iOS, free) fat-burning workout uses the principles of tabata, which calls for eight 20-seconds bursts of power separated by 10-second breaks, resulting in a four-minute calorie-buster.
Exercises include running in place, jumping jacks, push-ups and burpees (think: push-ups with jumps). GIFs demonstrate the exercise, but you also have to watch the clock, which silently counts down the seconds remaining. Dings at the five-second mark give start and stop warnings. Watching the clock can be annoying – distracting, even. Users can opt to pay to access general and instructional voice-overs.
Slightly longer, the 7 Minute Workout (iOS, free) is the most customizable of the three reviewed here. You can set up reminders to get to it, adjust interval and rest times, and pick the instructor’s gender and type, such as drill sergeant or cheerleader. The app comes with the full-body workout, 12 30-second exercises that include planks, crunches and triceps dips. Every second month, you get another workout free, or unlock more, such as Insane Abs or Office Chair, for $2.99 each or by joining the 7 Club for $4.99 per month.
Unlike the others, the 12 Minute Athlete app (iOS, $2.99; Android, $1.99) gives options to use your own bodyweight or props, such as a jump rope, kettlebell or medicine ball. It also offers a 16-minute workout and a challenge workout in which you can do as many reps in a set as you’d like.
A ding means it’s go time, and a robotic voice tells you what exercise to do. Watch the clock count down the 30 seconds per exercise and the 10-second rest.
All three apps offer written and video instructions for performing each exercise, but some knowledge of proper form going in will help you avoid injuries. HIIT is a great way to make workouts challenging and engaging. A 10-second break isn’t enough time to get bored.