Mix-and-Match Boot-Camp Workout
Lower body: Single-leg squats
Hold a 5- to 8-pound dumbbell between both hands, arms extended forward at shoulder height; stand with feet hip-width apart. Raise your right leg directly in front of your right hip, keeping leg straight. Bend your left knee as deeply as you can, then straighten it again. Do all reps on one side, then switch sides and repeat.