Exhale as you raise your body back to the starting position. Do this gently and slowly so you do not hyperextend your shoulders. Be sure to retract your shoulder blades and keep your shoulders square and stabilized (not rolled forward or up). As soon as it is difficult to hold your shoulders still and pulled back, stop the range of motion. This is 1 rep. Repeat this exercise for 2 sets of 10 reps. You should feel your tricep muscles working after 2 sets of this exercise.
While many arms exercises are biceps-focused, this simple isolation exercise dials in on the triceps, or the backs of your arms. (If you do find your biceps working overtime, this is a great way to make sure you're building balanced upper-body strength.) "By hugging your elbows in toward your body and using your own bodyweight, this area is majorly targeted," says Speir. And it's really easy to do anywhere. "The great thing about this move is it takes up the smallest amount of space," she adds.
The skin also serves as a release point for heat. (See “Why Does My Face Turn Red When I Exercise?” for more on that.) When you exercise, your muscles generate a lot of heat, which you have to give up to the environment so your body temperature doesn’t get too high, Hackney says. The heat in the muscle transfers to the blood, which shuttles it to the skin; it can then escape into the atmosphere.