Dumbbell Thrusters

• Stand with your legs just slightly wider than hip-distance apart, arms raised to shoulder height with elbows bent, holding weights by your ears.
• Bend your knees as if you were sitting in a chair, keeping weight on your heels.
• Press the dumbbells overhead as you straighten your knees to return to standing.
• Continue for a total of 40 seconds. Take a 20-second rest.

Alternating Forward Lunges With Biceps Curls

• Stand tall with your feet hip-width distance apart. Hold a dumbbell in each hand at your sides.
• Step forward with the right foot as you bend the elbows in a biceps curl. Lower your hips until both knees are bent at about a 90-degree angle. Keep the front knee directly above the ankle and lower the left knee to just tap the floor.
• Keep the weight in your heels as you push back to the starting position, completing one rep.
• Repeat stepping with the left foot this time, completing a second rep.
• Keep alternating for 40 seconds. Rest for 20 seconds.

Dumbbell (Kettlebell) Swing

• Stand with your legs shoulder-width distance apart and toes pointed slightly outward, holding the dumbbell (or a kettlebell, if you have it) in both hands.
• Bend the knees slightly, pushing the hips back and lowering the weight between your legs with the forearms pressing against the inner thighs. Keep your chest open with shoulder blades sliding down your back.
• Forcefully squeeze your glutes and drive the heels down to thrust the weight forward as you straighten the legs. All the work is done by the lower body and core in this exercise, and your arms will naturally swing forward to around chest height or above the head.
• Allow the weight to fall between your legs, bending the knees to ready for the next rep.
• Do as many swings as you can for 40 seconds. Take a 20-second rest.

Here's how to do this move with a kettlebell [2]. If this move seems too advanced or you have an injury, do goblet squats [3] instead.

Side Lunge to Curtsy Squat

• Holding a dumbbell at your chest, step your left leg wide to the left, coming into a lateral lunge, bending your left knee. Keep your chest lifted and your weight in your left heel.
• Push off with your left foot and cross the left leg behind your right, coming into a curtsy, bending both knees. This completes one rep.
• Step out to the left, returning to your side lunge.
• Continue alternating between these two moves for 20 seconds. Repeat on the other side for another 20 seconds.
• Take a 20-second rest.

Box Jumps

• Stand in front of a box. If you're new to box jumps, choose a box that's 12 inches high. If you're more advanced or taller, go for a 24-inch box.
• Use your starting position to set up the entire movement: engage your core, bend at the knees, and allow your arms to provide you with momentum, jumping onto the top of the box. If this is too hard, just step up with one foot at a time.
• Step down with one foot at a time to complete one rep.
• Do 40 seconds of box jumps. Take a 20-second rest.

If box jumps aren't for you or you don't have access to a box, do jump squats [4] instead.

Single-Leg Bridge Kicks

• Lie on your back, and place your hands on the floor for stability as you bend one leg and lift the other leg off the ground.
• Pressing your heel into the floor, lift your pelvis up, keeping your body in a stiff bridge position.
• Slowly lower your body to the floor.
• This counts as one rep. Continue on one side for 20 seconds. Repeat on the other side for another 20 seconds.
• Take a 20-second rest.

Dumbbell Sumo Squat

• Stand with your feet wide, toes pointing out, and hold both dumbbells in front of the chest. Bend your knees, lowering your hips deeply, so your thighs are parallel with the floor. Make sure to keep your weight back in your heels.
• Rise back up, straightening the legs completely and squeezing the glutes at the top of the movement to get the most from the exercise.
• This completes one rep.
• Do as many reps as you can for 40 seconds. Take a 20-second rest.

Wall Sit

• Stand with your back against a wall, placing your feet about two feet in front of you. Feet should be hip-distance apart.
• Bending your knees, slide your back down the wall until your knees are at 90-degree angles. Your knee joints should be over your ankle joints, so you may need to inch your feet farther from the wall to create proper alignment. Don't let your knees fall into the midline of your body or sway outward.
• Hold for 40 seconds, then stand up and rest for 20 seconds.