What are the biggest leg press mistakes?

June 25, 2016

Q: I often see people in the gym using the leg press machine but feel they use a lot of bad form, adding more weight than they can handle properly and putting themselves at risk of injury. What are your thoughts on this issue? What advice would you offer to guide people how to do this exercise correctly?

A:The leg press is a great machine for isolating the legs and is accessible at almost any traditional gym but you must use it correctly or you will not get the results you're looking for and may even get injured in the process. Below are five things that I like to stress when teaching the leg press to new clients.

Use proper foot position
You can vary foot position to isolate different parts of the quadriceps - four leg muscles in the front of the thigh - but the best way to learn to do this exercise properly is with feet shoulders’ width with toes slightly angled out away from the body. Using a shoulders’ width stance puts the thighs under direct pressure for maximum muscle fiber recruitment, allowing you to get an incredible burn for every rep you complete, which is optimal for leg strength and muscle gains. Also, angling your toes slightly outward allows the knees to function safely, putting less stress on the joint and instead placing it on the leg muscles where it belongs.

Position knees correctly
The biggest mistake I see with the leg press is using a narrow stance and allowing the knees to turn inward, touching or bouncing off the stomach. This error encourages people to load the machine with dangerous weight they couldn't normally handle, and it takes a great deal of tension off the legs. To perform this exercise correctly I have my clients turn their knees slightly outward before they begin to lower the weight and their thighs even with the sides of their body as they descend. This way the legs do all the work and they can only lift weight that is appropriate.

Adjust depth to your goals
How deep you bend into the movement depends on your goals and what muscles you're trying to target. If you want to isolate your quads – front of the thigh - stop when your thighs and shins are at a 90-degree angle and pause, forcing the front of the legs to receive the brunt of the pressure, then return back to the starting position, keeping your legs flexed and tight an inch from locking the knees. If you would rather target your hamstrings and glutes- back of the legs and butt - go 1 to 2 inches below parallel with the same pause at the top and bottom of the movement and you will shift the focus to different muscles while still involving the entire leg.

Don't lock out at the top
A locked joint is a rested muscle, because the tension of the movement is no longer placed on the legs where it belongs; it's transferred to the connective tissue like the knees and spine. Get the longest and most complete range of motion possible, but make sure you keep your knees from locking out at the top of the movement to keep the muscle under pressure, activating as many muscle fibers as possible. To accomplish this goal stop approximately 1 inch from fully extending the knees at the top of the movement and I guarantee your legs will burn twice as much as they normally do when performing this exercise.

Don't use too much weight
Once you try the above techniques you will more than likely have to drop the weight you use on the leg press because you will be isolating the leg muscles a lot more and the intense burn will keep you from overloading the machine. Just to be safe, be sure to use weights you can handle and incorporate a split-second pause at the top and bottom of the movement. This will force the legs to lift the weight, eliminating momentum, protecting the knees and spine, giving you a lot more bang for your buck when it comes to results.

  • Chris Antonio is a personal trainer and former world-class weightlifter. He has been lifting for more than 20 years and has trained a wide variety of clients ranging from All-American athletes to the average person trying to get into shape. To send a question to the Ask the Trainer column, email Chris at or check out

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