Leg day training can be brutal (although, thanks to Crossfit, more and more people are embracing it), but its completely worthwhile, perhaps more important than any other day. Training your legs challenges your entire body, for a variety of reasons. Your upper body, after all, has to hold all that weight. You can also, in general, go heavier on leg days than you can when training, say, your arms, and hitting your body with all that weight will drive a strong hormone response throughout the entire body, burn calories, and incinerate fat in the process.

Leg trainings come a long way in recent years, too. Its not all back squats, and its not all big-box machines like leg extensions and curls, either. There's a host of variety on today's leg days. Not sure where to start? These exercises are a good bunch to master in your quest for major wheels.

Front Squat

There are an endless variety of barbell squat variations, but perhaps no option gives you more bang for your buck than the front squat. The front-loaded nature of the move is going to push you to develop shoulder, ankle and hip mobility, and here's the best part of all: Your entire core has to be firing the entire time to protect your spine and make the move possible. Its an ab workout wrapped in a leg workout.

Hill Sprints

When is a sprint not merely a sprint? When you're trying to sprint uphill. Whether you're doing that on a treadmill or on an actual hill, you'll be hammering your glutes and quads, and you'll naturally be honing better sprint form, simply because of the challenge of the angle of the hill. Make sure you sprint for no more than 20 seconds at a time, though (with solid rest in between). Go much longer than that, and you're basically just running uphill instead of actually sprinting.

Backward Sled Push

More and more gyms have sleds and performance turf inside; if yours does, you should take advantage. But that doesn't just mean pushing and pulling the sled. Attach some bands to the sled for support, lean against it, and push it in reverse. You'll be forced to extend aggressively at the knees, a key function of your quads. Expect major quad burn.