The best exercises for bad knees are those that target the muscles supporting the knee without placing weight-bearing stress or causing undue flexion (bending) of the knee itself. These 12 exercises ...

If you want legs that command attention, you have to balance strength and size. Squats and deadlifts will crush your glutes and hamstrings, helping you to pack on serious power. But if you want quads ...

b) Press lower back into the floor, straighten legs to 45-degree angle, return to tabletop. Repeat.

Beth Skwarecki is Lifehacker’s Senior Health Editor, and holds certifications as a personal trainer and weightlifting coach. She has been writing about health for over 10 years. Ready for leg day?

Jakob Roze, CSCS, is a health writer and high-end personal trainer. He is the founder and CEO of RozeFit, a high-end concierge personal training practice and online blog. Squats train all the major ...