Our own Class FitSugar host Anna Renderer (MS, Exercise Physiology) is not particularly fond of front lunges. "The sheer force and pressure this move puts on the knee joint is not worth the benefit." She feels that unless you're an athlete, it's best to avoid this move since there are so many other effective lower-body exercises that don't compromise the knee joint. Anna's list of alternative exercises that safely and effectively work quadriceps, glutes, and hamstrings includes: walking lunges, reverse lunges, single-leg squats, and Bulgarian split squats.
Here are detailed instructions for the Bulgarian split squat; elevating the back foot increases the difficulty of the move, but you can also do the move with both feet on the floor.
