The latest science says that this simple shift—speeding the pace of your sets—accelerates your strength gains. Here's exactly how to tap the effect.
Much has been made of the advantages of doing high-intensity intervals (a.k.a. sprints) versus steady cardio, but new research has found a similar boost applies to strength training. In a study from the American Council on Exercise, exercisers who did five-rep sets quickly with shorter rest in between (called HIIT style) got the same or better results in muscle fitness compared with those who did traditional moderate-intensity strength sets—even though the latter group was doing more reps for twice as long (45 minutes versus 20).
"The HIIT workout was better at providing that necessary stimulus to the muscles to have a more favorable training adaptation," says lead researcher Lance Dalleck, Ph.D.
In other words, HIIT netted a slightly better strength boost in half the weekly time commitment. The fact that the HIIT exercisers also used the max weight they could muster for exactly five reps was key in pushing their muscles to their limit—the sweet spot you want to be at, Dalleck says. (Related: What Really Happens When Women Lift Heavy Weights)
Put this science into practice with the mini circuit below by Autumn Calabrese, the creator of the 80 Day Obsession programs. She designed it to check off two boxes: "If you're doing the right move, with the right weight, why not do it HIIT style to get that two-for-one of strength training benefits plus cardio benefits?"
Aim to do this workout or other HIIT training no more than three times a week. "The higher intensity requires more time for your muscles to recover between bouts," says Heather Milton, a clinical specialist exercise physiologist at NYU Langone Sports Performance Center in New York City. "Three times per week with 48 hours of rest in between is that ideal spacing when you can get the benefits without increasing the injury risk."
How it works: Grab a set of weights that feel challenging for the number of reps listed, and do two sets each at a fast clip.
Total Time: up to 15 minutes
1. Sumo Press
Stand with feet wide and toes turned out, holding 1 weight at ends with both hands in front of chest to start. Squat, rotating torso to right and reaching weight above right foot (arms go on both sides of knee).
Stand, curling weight to chest, then press it overhead as you rise onto balls of feet. Return to start position. Switch sides; repeat. That’s 1 rep.
10 per side
2. Single-Leg Squat Press
Stand with feet hip-width apart, holding 1 weight at ends with both hands at chest level to start. Lift left foot off floor. Squat as low as you can. Stand, lift left knee to hip level.
Press weight overhead as you straighten and extend left leg to side. Return to start position. That’s 1 rep. Do 10 reps. Switch sides; repeat.
10 per side
3. Lunge-Kick Kickback
Stand with feet together, a weight in each hand, arms by sides to start. Lunge forward with left leg, bending both knees 90 degrees. Push off left leg to kick left foot forward. Without touching floor, step left leg back into a reverse lunge, bending both knees 90 degrees.
Lean forward from waist, bring weights
to ribs, and extend arms back with palms facing
in. Return to start position. That’s 1 rep. Do 10 reps. Switch sides; repeat.
10 per side