Legs

Barbell Lunges

Barbell lunges put the weight on your back: legs and glutes work under a squat-like load, but each leg on its own.

Setup

Set the bar on your upper back as for a squat and walk it out. Stand tall, feet hip-width. Abs braced, eyes forward.

Unrack the bar across your upper back, feet shoulder-width apart — starting position.
Inhale and step forward, bending both knees, torso upright.
Exhale and push off your heel back to the starting position. Repeat on the other leg.

Stepping onto one line like a tightrope — keep your feet hip-width or you'll lose balance.
Back knee slamming the floor — come close, but touch softly.
Torso folding forward — keep your chest up.
Short step with the knee far past your toes — step so your front shin is nearly vertical at the bottom.

Not sure about your form? Send me a video of a set — I'll take a look and tell you what to fix first.