are an excellent way to use your lower body to elevate your heart rate. But if you need to keep things low impact, or just want to switch to an upper-body cardio move, try this exercise instead (it's harder than it looks).
To do it: Stand with your feet hip-width apart, both arms extended out in front of your chest, palms facing down, thumbs touching.
Squat down by bending your knees and sitting back into your hips as you quickly sweep your right arm down and back, making a circle from back to front, bringing your right arm on top of your left. Immediately switch to your left arm and do the same (like you are swimming).
Continue alternating arms, making your circles as large and as quick as you can, powering through your legs with each stroke. Try to do this for 60 seconds.
Options:For more intensity, make this a plyometric move by adding a little hop at the top of your squat as you finish each stroke.