Lovitt likes to combine two lower-body classics—a curtsy lunge and reverse lunge—into one creative exercise to mix things up. "It’s a fun, effective compound movement." Compound movements are exercises that engage more than one major muscle group, so you get more work done in less time—this one primarily works your glutes, quads, hamstrings, and inner thighs (and helps keep things fresh if you're bored of working your lower body with regular bodyweight squats or lunges). This specific combination goes like this: curtsy lunge, reverse lunge, hop (bonus!), reverse lunge, repeat.
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.