This exercise should be incorporated in your routine if you're an athlete looking to increase explosiveness (acceleration, top speed, and vertical) and size to your legs.
This exercise exploits the big 3 muscle groups that make up majority of your legs anatomy (quads, hamstrings, glutes). It also incorporates calves, along with stability muscle groups like adductor/abductor muscles.
Not to mention, it also targets core strength, being it's a single leg exercise that requires a lot of balance.
Set the barbell at the appropriate height, keeping the hanging leg at a 90 degree bend through the knee while standing.
To incorporate all muscle groups, your hanging leg should be aligned just behind the working leg.
Allow the knee of your working leg to slide past your toes before firing back into full extension, helps activate the quads.
Dip your hanging knee to just above the floor or slightly tap the floor before firing back into full extension, this depth helps activate both your hamstrings and glutes.
Keep dumbbell flush to your hanging leg to help with balance.
Chest up, shoulder blades back.
Supporting arm stationed roughly at half your height for best stability throughout the exercise.
Using this rack set up offers the best stability and hanging leg comfort compared to your usual, no rack, bench set up.