If it's so hot you have to wear shorts, you might as well have the legs to go with 'em. Squats, done properly, can add strength and tone to your gams. But do them wrong and your knees won't appreciate it. Here's 5 tips for making sure you squat like a champ.

1. Make sure you have a nice curve in your lower back (lumbar spine.) The easiest way to get this is to, um, stick out your chest and your booty. Think RuPaul doing "Supermodel".

2. Your knees should never stick out past your toes. If you look down and you can't see your feet, your knees have slipped too far forward.

3. Most of your weight should stay on your heels. As you bend your knees, wiggle your big toes. Can you do it? Good job.

4. Ideally, at the bottom of a squat your thighs should be parallel to the floor. If you are starting out, work up to this.

5. Look up! Yeah, I told you to check your feet, but once you've done that, keep your eyes on a nice, high spot. It'll help prevent you from hunching over your chest.

Now do lots and enjoy the leg burn...and the results.