20-minute workout: dumbbell HIIT

The Pro: Sam Rothermel, group fitness instructor (Pro Strength, METCON, and Barre) at Equinox in New York City

The Workout: Full-body, compound movements can do wonders when you’re short on time and looking to boost your overall fitness. Up the intensity and throw in some dumbbells, as you do in the following routine, and you’re guaranteed to feel accomplished after just 20 minutes. “This workout is metabolic conditioning-based, so you’re reaping the benefits of both resistance training and high-intensity cardio all at once. Plus, it gets you moving in all three planes of motion, so not only are you burning fat and conditioning your muscles, but you're also improving mobility and engaging your core throughout,” says Rothermel. All you need is two sets of dumbbells—one heavy (for lower body) and one moderate (for upper body)—to begin.

Complete the warm-up to prep your body for movement, going from standing, down to the floor, and back up again. Then perform the circuit, moving from one exercise to the next without rest. Once finished, rest for 90 seconds, and repeat. For best results, do this workout two to three times (with rest days in between) each week.

Warm-up (3 minutes)

Perform each exercise for 30 seconds, and then move on to the next one.

1. Jack with Alternating Reverse Lunge

Stand with feet hip-width apart, arms extended by sides. Perform a jumping jack, and as you return to starting position, step right leg back into a lunge, with both knees bent. Press into the ball of your right foot to return to start and repeat, lunging back with left leg. Continue alternating sides throughout.

2. Alternating Lateral Lunge with Ankle Reach

Stand with feet hip-width apart, arms by sides. Lunge right leg out to right, bending right knee and keeping left leg straight, as you reach left hand to touch right ankle and extend right arm toward ceiling. Press into the ball of your right foot to return to start and repeat, lunging to left. Continue alternating sides throughout.

3. Bodyweight Squat into Inchworm

Stand with feet shoulder-width apart, toes turned out to sides slightly. Squat, bending knees 90 degrees, sinking glutes toward floor. At the bottom of the squat, walk hands out in front of you to plank position (palms under shoulders, abs engaged, and toes tucked under), and perform a push-up. Walk hands back to squat position, and then press through heels to stand up. Repeat.

4. Dynamic Beast with Shoulder Taps

Start on all-fours, with palms under shoulders, knees under hips. Tuck toes under and lift knees a couple inches off the floor. Keeping abs engaged, drive hips back a few inches, bringing chest closer to thighs. Press through toes to return to “beast position,” and then tap left shoulder with right hand, lower; tap right shoulder with left hand, lower. Maintaining “beast” position, repeat hip press and shoulder taps.

5. Jump Squats

Stand with feet shoulder-width apart, arms extended by sides. Squat, bending knees, sending hips behind you, and then press into the balls of your feet to jump straight up in the air; land softly back in squat position. Repeat.

6. High Knees

Stand with feet hip-width apart, arms bent by sides. Drive right knee toward chest, pressing left arm forward; right arm back (as if running). Hop off ball of left foot and switch arms and legs mid-air, so left knee is bent in front of you and right arm is forward.

DUMBBELL HIIT (17 minutes)

Perform this workout as a circuit, completing each exercise for 1 minute and then immediately moving onto the next, without rest. When finished, rest for 90 seconds and then repeat the entire circuit.