jump out with feet as wide apart as is comfortable as arms lift out to the sides and up to shoulder-level.
When you jump back in, cross your right arm over your left at mid-chest and cross your right leg over your left leg. Jump back out, then jump in as you reverse arm and leg positions. Continue alternating right and left until you’ve completed 10 to 20 jumps in all.
You don’t have to hold a barbell while doing squats for them to effectively work the muscles in your legs and butt. Stand up straight with feet shoulder-width apart and slightly turned out. Place your hands on the back of your head so you can’t use them for momentum.
Lower your body, bending at your knees, with the goal of bringing your thighs parallel to the ground. Go only as far as you comfortably can, but aim to go deeper with practice. Hold for a count of one before straightening to the start position.
Repeat up to 15 times for one set. As you progress, increase the number of sets you do in each session.
More information
The American Council on Exercise has more bodyweight exercises to add to your regimen.