Quads Hams Glutes
With Charles
This is an extremely intense leg workout. It's vitally important to perform this on a soft surface, such as carpet or a workout mat.
Please start with low resistance and gradually increase it over time. You do not need to push yourself to failure during your initial attempts.
Work up to it. Be aware that going to failure can cause you to fall over, which can be dangerous if you're not in a safe environment.
Exercise good judgment. You can still achieve a great workout without pushing to failure. There is nothing wrong with stopping a few reps before failure, taking a break, and then doing another set.