If you were initiated into the world of fitness under the tutelage of a high school P.E. teacher or a personal trainer at a massive commercial gym franchise, the leg extension may be the first resistance exercise for legs that you’ve encountered. The reason for this is because educators are often paranoid about trainees getting injured on their watch, and leg extensions are among the simplest and safest leg exercises to learn in a controlled fitness environment. While most tried-and-true methods for training legs with weights require multi-joint movement, leg extensions only necessitate the straightening of a previously bent leg against consistent resistance. Given the simplicity and effectiveness of leg extensions it isn’t shocking that you would relish an opportunity to reliably perform them in your home gym without having to swipe an entire leg extension machine and secretly stash it in your garage. Credit: YAKOBCHUK VIACHESLAV / Shutterstock Your only hurdle now is figuring...