Q+A: Is the Leg Press a safe exercise? My answer may surprise you.

The Leg Press Exercise

The Leg Press Exercise

I received this question in the Burn The Fat: Inner Circle today, and thought you may learn something new from my answer.

QUESTION: Hi, I read in the New Rules of Lifting that using the leg press is not recommended, it puts too much pressure on the lower back. Any opinions on this would be appreciated.

Technique and incremental progression are both very important to ensure you stay injury free, but you should also factor in the training tool you are using. Not all training tools were created equal.

Alwyn Cosgrove is wise to steer people away from the leg press for many reasons. Lower back injury is one of the most common problems that leg pressers experience, but it’s the progression to lower back problems that you should be concerned about.

First, a brief explanation…

Compound and free weight movements are not only more productive from a work capacity standpoint, they’re also safer than machine-based “muscle isolation” exercises. Many trainers have convinced their clients that machines are safer than free weights, and that (for example) leg extensions or smith machine squats are safer than barbell squats. Of course, anything CAN hurt you, but machines force you into a pre-determined movement pattern. The danger is present because if forces exceed your structural capacity, you can’t escape and will get injured. With free weights, you can quickly modify your positioning to escape injury. The same idea can be applied to single-joint versus multi-joint exercises. This is why no one ever tests their one repetition max on exercises like bicep curls or dumbbell lateral arm raises — it’s dangerous and inefficient because all of the load is focused on a single joint.

Most of the time, problems arise from doing the same movement over and over again (as in a baseball pitcher throwing a pitch or a landscaper pushing a mower all day), or, in the case of the fitness trainee, using machines that force you into using a physiologically “unnatural” and inefficient movement pattern. Also, machine training cannot be individualized, even with machine seat adjustments, because every person has a different structure and conditioned movement patterns. Do you think the application of strength in the leg press exercise will be any different for someone who has longer legs compared to someone with shorter legs? You bet it is – the leverage of the exercise can change entirely, making the corresponding muscles and joints to differ in their function from trainee to trainee. The net result? At its most severe, joint injuries. At its best, lack of progress.

So, what happens when you force your body to do work in an unnatural movement pattern? First, you condition breathing, postural, and movement patterns – because everything is an act of conditioning, even sitting at a desk will improve your sitting abilities by shortening your hip flexors, rounding your shoulders, and extending your neck.

After you have been conditioned to do something like the leg press, you will progress to muscular adaptation and development (remember to an UNnatural training stimulus). After the muscles have adapted, the soft tissues will adapt and atrophy (ligaments, tendons, all connective tissues). It is at this stage that overall movement quality will be affected – even to the point of changing your everyday gait and posture, even when not exercising. Over time, this will result in joint misalignment and often spinal problems, which will eventually lead to further injury, illness, and the resulting pain (FINALLY, we get a signal from the body that we’re doing something wrong!)

This entire process can spiral downwards, and all the trainee knows is that they “have a nagging pain in their lumbar spine,” or they “can’t train today because that old shoulder injury is bothering them again.” When, in reality, there is quite a bit of damage that has already been done.

I recommend training with weight machines such as nautilus or life fitness if someone is a beginner to exercise, or as needed in a rehabilitation environment – when a large amount of control is needed for the PT. Anyone else should steer clear of them.

So, if you’re a newbie to fitness, resistance training machines are fine for now, but lose the training wheels and move on to free weights as soon as your confidence allow. Muscles respond best when they’re required to control weights, not just push against them.

One last note – life and athletics often takes place on our feet. Not sitting down, laying down, or wearing a seatbelt.

If you’d like to learn more…


Here is an excerpt from an article I wrote about the hierarchy of training tools.

15. Resistance Training Machines (such as Nautilus and Life Fitness)

Defined: Resistance training machines use gravity as the primary source of resistance. Each of the simple machines (pulley, lever, wheel, incline) changes the mechanical advantage of the overall machine relative to the weight and the user when standing, sitting, or lying down. These machines are incredibly efficient in and of themselves, meaning that they don’t require the user to move efficiently – effectively training the body to be inefficient. This makes resistance training machines pretty poor tools for strength training for most individuals.

Best if used for:
• Rehabilitation from injury as advised by your doctor or physical therapist.
• Introduction to weight training.
• Targeting specific areas of muscles that cannot otherwise be stimulated through other methods (see below about pro bodybuilders)

• Easy learning curve.
• Useful and sometimes essential in rehabilitation settings after chronic injuries.
• Professional bodybuilders have been known to receive good stimulus through machine-based training, when targeting specific areas of a body part that is difficult to simulate with other tools like free weights.

• Performed in a fixed-axis, so there is no need for stabilizer muscles to fire. Also, our bodies rarely move in straight lines. Even the free weight version of a barbell bench press is performed in a tight “J” pattern.
• The body is positioned within boundaries against padded cushions, so the exercise is limited to pressing against weight. Your body needs to learn how to control weights, not just to press against them. Teaching your body how to move in this way will result in inefficient movements in everyday life, and will actually “dumb down” your nervous system.
• Designed to try to isolate muscles, which any anatomy student will tell you is impossible. No single activity, athletic or not, requires or allows the isolation of muscles. Even a biceps curl uses the back muscles, gluteal muscles, hamstrings, and calves. Think about it, when you hold something out in front of you, your entire “backside” will have to contract to keep you in balance. Why would we need to train in a non-functional way?
• Performed sitting down or laying down. Most everyday activities and athletic movements are not performed sitting down or laying down. Again, why would we need to train this way?
• Machines are designed to accommodate as many body types as possible, making it impossible to design a machine that fits everyone. Even with seat adjustments (etc.), widely different movements occur with different people simply because no size fits all.
• Machine weights cannot be dropped in case of an emergency – like muscle failure. If injury occurs or trainee pushes too hard the weights cannot be dropped safely like free weights can. The weight stack will come crashing down along with the respective handles, footpads, (etc.) possibly causing injury to the person using it.
• These machines are expensive and take up a lot of space.
• Many studies have proven that machines: decrease functional strength for free weight movements, decrease overall power output, decrease neural efficiency, shorten muscles, and decrease flexibility. Overall, machines teach the body to be dysfunctional.

Common mistakes:
• Using machines outside of the recommended parameters above.
• Not adjusting the machine for your body type (ie, seat height).
• Using too much or not enough weight.
• Slamming the weight stacks down.
• Not keeping your body in contact with the appropriate padding at all times (ie, arching back, lifting head off of pad, etc.)

Best place to find: Your local health clubs will probably be stocked with a full line of resistance training machines, and will probably have them setup in circuit style. Because these machines are bulky and very expensive, they are not ideal for home gym training.

Your Question of the Day is: what training tools have you graduated to using in your program?

To your health and success,

Fitness Professional and Resistance Training Machine Antagonizer

P.S. There is a whole discussion about this topic in the Burn the Fat: Inner Circle forums. If you have fat loss goals and want some community social support, along with all the tools you could ever need to help you achieve your body composition goals, then head on over there.

10 comments to Q+A: Is the Leg Press a safe exercise? My answer may surprise you.

  • Rocko

    Hi John:
    Where can I find your article THE HIERARCHY OF TRAINING TOOLS? I would love to read the whole thing. Thanks.

  • John

    Hi Rocko,

    I actually haven’t finished that article yet. I meant to make it into a downloadable PDF, but just haven’t had the time. It’s a big project, and the blog hasn’t taken my top priority lately.

    I made a note to finish it, and you can be sure that I’ll announce it once it’s finished.



  • Jeri Sabo

    I had a total right knee replacement three months ago. I have been under going PT since. I’ve had a diagnosis of lumbar spinal stenosis for some time. Numbness in both legs and feet developed overnight about five weeks ago. Could it be the leg press?

  • John

    Hi Jeri,

    Thanks for stopping in.

    It’s possible that your injuries could have occurred in part due to the leg press exercise, or any other unnatural exercise for that matter. However, it’s impossible to know for sure. Your physical therapist should be able to trace some of your movement patterns to discover the source of the problem. It would be impossible for me to offer any sort of advice on this matter.

    I hope you understand. Best of luck with your recovery.

    Best regards,


  • Jeri

    John, Thank you for your prompt response. Have there been any recent studies addressing this possibility? I have not been able to find anything definative. Jeri

  • John

    I haven’t read any specific studies linking the leg press to injury. I HAVE read studies linking it to stalled progress, and diminishing returns in a training program, which are the first steps in the cycle of injury and dis-ease.

  • Brenda PT

    As a physical therapist, I would NOT agree with your statement that a leg press is an “un-natural” exercise. This duplicates other closed chain functional activities like getting up from a chair, and taking a step down on stairs; activities that are some of the most challanging ones after knee replacement. The key is in the setting of the machine (light weight, low reps and putting the sled far enough away that there is 90 degrees or less of flexion in the knee when the resistance occurs. For patients with a history of back pain, it is vital to be cued to hold a pelvic tilt/ back flat position during the leg press at all times. Under no circumstances should one have back pain with leg press. My advice when it comes to the use of equipment like a leg press after a surgical procedure of any kind is to consult a physician or your physical therapist. They do know your individual medical needs and abilities and can adjust accordingly. I DO agree that there are several other exercises available for use prior to using the leg press. But in general terms, closed chain activities (where the foot is planted) are much safer than open chain activities (like leg extension, or full arc exercises with a leg weight on the ankle) after knee replacement as they place much less tourque on the replacement itself. B Fitzgerald, PT

  • Brenda, I think the point that you are missing is that “getting up from a chair” one is not strapped to anything and we aren’t generally lying on our backs (at least the chairs in my house aren’t anyway). When we get up from chairs we aren’t in a “fixed axis” position and still use other muscles to control the movement. Likewise stepping down stairs.

    So you’re basically wrong.

  • GVelo

    I have been training for a few months using the leg press to strenghten my quads and improve my power for cycling. My choripractor advised me against using it because of the pressure it applies on my lower back combined with the fact that, being in my early 50s, it would accelerate the degenerative process. Is there any other exercice I could do that would replace what I was doing on the leg press?
    Thank you

    • John

      Hi GVelo,

      Assuming you’ve been cleared for exercise by your doctor, and also assuming you can do the following without pain, I’d recommend the bodyweight squat as the preferred training exercise. The split squat would also be another good one to try. Although, you could also experiment with various lunge exercises (forward lunges, reverse lunges, walking lunges, lateral lunges, plie lunges, dragon twisting, etc.).

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