Functional strength gains by leg pressing?

The following article is a guest post from Chris Beardsley, who writes the monthly Strength & Conditioning Research Review service with me:

Some popular strength coaches have claimed that the leg press does not build “functional strength”.

Functional strength refers to basic movements that we all need to perform on a daily basis, like getting out of a chair, climbing up and down stairs, and walking across town. It can also refer to athletic performance measures, like vertical jump height, horizontal jump distance, and short-distance sprinting ability.

Since a small number of research studies have actually investigated whether leg press training leads to improvements in such tests of real-world muscular function, we can put these claims to the test.

Why believe that the leg press does not build functional strength?

As far as I can tell, the idea that the leg press does not build functional strength came about through the following process.

  • Originally (and not really that long ago, actually), few athletes trained with weights. Those who did used free weights because that was all that was available.
  • Later, machines became more widely available and their manufacturers presented them as viable alternatives to free weights.
  • Athletes began to train with weights more often. Coaches found that closed-chain, free-weight exercises like the squat transferred better to sports performance than machine exercises like the leg press. Many athletes were happier using machines, though, even if that meant suboptimal results.
  • To motivate athletes to use free-weight exercises, some strength coaches invented the idea that training with machines doesn’t work. Since they couldn’t claim that machines don’t improve strength (because they clearly do), they said that machines don’t improve “functional strength”.

Let’s assess whether that claim holds any water whatsoever by looking at the research. But before we get started, let’s clarify what the term “functional strength” actually means.

Avoid the leg press?

Should we really avoid the leg press?

What is functional strength?

Functional strength is the ability to display muscular strength in a basic human movement, such as walking, running, jumping, squatting, deadlifting, or lunging. If you wanted, you could add in dragging, carrying, throwing, and even climbing in there. You get the idea.

The term “functional strength” comes from the field of gerontology, where researchers work hard to help elderly people become more mobile, more independent, and less likely to fall down. In their world, improving “functional strength” is a critically-important issue. It refers to the ability of these people to perform tasks such as walking, getting up out of a chair, recovering balance, and climbing stairs. For these researchers, increasing functional strength means making a real difference in a person’s life. So they take discussion of the methods that improve it very seriously, as should we.

Does the leg press improve functional strength?

If the leg press does not improve functional strength, we would expect a resistance-training program using only that machine (or in combination with other machines) to increase leg press 1RM but not improve walking, running, jumping or squatting abilities. Is that really true? Let’s take a long, hard look at the research. There’s not a lot of it, I admit, but what there is all points in the same direction.

Let’s get the stuff that’s only applicable to diseased populations out of the way first, shall we? I bet I’m going to catch hell for it in the comments, anyway. With that in mind, here are a couple of studies that show how leg press training helps sick people walk better. If you can get any more “functional” than that, let me know.

Karlsen and Helgerud (2009) published a study in International Journal of Sports Medicine. They used an 8-week training program, involving 4 sets of 4 reps with a horizontal leg press at ~85% of 1RM with 2 minutes rest between sets, 3 times per week. Not only did leg press 1RM increase 44% but walking efficiency (oxygen consumed for the same workload) improved by 35%.

The marvelously-named Wang et al. (2010) published a study in Scandinavian Journal of Medicine & Science in Sports. They used a similar, 8-week training program involving 4 sets of 5 reps of the leg press at ~85% of 1RM, 3 times a week. Leg press 1RM increased 31%, walking economy increased 10%, and performance in a treadmill test to exhaustion increased 14%.

So if you know someone who is very out of shape and whose health isn’t the best, and who needs to get better at walking, leg press training could help them build some functional strength that would help improve that.

Leg press machine diagram top

I’m guessing that some readers are going to tell me that older people are a different species from young people, too, but let’s cover off what happens when the elderly start leg pressing.

Very recently, Pamukoff et al. (2014) published a study in Clinical Interventions in Aging. Their study assessed the effects of a 6-week, machine-based lower-body resistance-training program on a single-step balance recovery task. The exercises included the leg press, knee extension, leg curl, hip abduction, hip adduction, hip flexion, and calf press, all of which were performed for 2 sets of 8 – 10 reps at 50% of 1RM. Leg press 1RM improved by 20% and improvements on the balance recovery tasks increased by 30%.

More impressively, Correa et al. (2012) released a study in International Journal of Sports Medicine. They used a 12-week periodized program of leg press, knee extension, and knee flexion exercises, performed 2 times a week. They found that jump height increased by 8 – 10cm while the number of bodyweight squats performed in 30 seconds improved by 18!

In a brand-new study in Experimental Gerontology, Ramírez-Campillo et al. (2014) had their elderly subjects perform both upper- and lower-body exercises (bench press, standing upper row, biceps curl, leg press, prone leg curl and leg extension) as well as some core work. The subjects trained using 3 sets of each exercise for 8 reps at 75% of 1RM, with 1-minute rest between sets. Before and after the 12-week training period, the researchers found improvements in jump height, 10m sprint time, and number of bodyweight squats in 30 seconds of 13%, 9%, and 19%, respectively.

I’m guessing that not many of you saw these results coming. Leg press training improves balance recovery, vertical jump height, number of bodyweight squats in 30 seconds, and short-distance sprinting ability. These are all good things as far as gerontologists are concerned. They’re also pretty useful when it comes to sporting performance. I guess that explains why so many British rugby teams still make heavy use of this supposedly non-functional piece of equipment.

Leg press machine diagram bottom

Far be it from me to pick only studies that have been performed in elderly or diseased populations. After all, strength coaches are generally employed to develop athletic performance in young people. So let’s look at how leg press training works in younger individuals.

In a study published inJournal of Athletic Training, Wawrzyniak et al. (1996) assessed the effects of 3 different 6-week leg press training programs on lower-extremity functional performance. In this study, “functional performance” was expressed by a maximal single-leg hop for distance. The 3 programs used different ranges of motion, including 0 – 60 degrees and 0 – 90 degrees of knee flexion. Perhaps surprisingly, it was the smaller ranges of motion group that improved single-leg hop most, by 6.5cm.

Wrapping up

Leg press training, either alone or with other lower-body, machine-based training, improves measurable, functional strength in most populations, including diseased, elderly and young people.

It can increase walking efficiency, balance, vertical jump height, horizontal jump distance, short-distance sprinting ability, and the maximum number of bodyweight squats you can achieve in 30 seconds. No, I agree, it probably won’t be as effective for improving athletic performance as the conventional back squat in trained populations… however, if you think it won’t improve functional strength at all, or if you believe that it will somehow magically make an athlete perform worse, then I have a bridge to sell you. There is simply no evidence to support that idea and what we do know suggests exactly the opposite.

For more articles from Chris Beardsley, please check out his blog.

 

23 Comments

  • Ben says:

    Thanks for sharing! I love compilations like this, you saved me a lot of leg work (pun absolutely intended). With the “functional fitness” trend and CF and such, it seems we have “thrown the baby out with the bath water” when it comes to machine work. Great stuff.

  • Sam says:

    Absolutely. Just look at all the dominant teams under Joe Paterno at Penn State. They trained primarily with machines for YEARS and their players were just as strong, athletic, functional as any other. Randy Moss (Vikings) and Darryl Green (Redskins) trained using machine-based HIT principles while in the NFL for years. Watch them play and try to tell me they didn’t have functional strength. It doesn’t matter what type of equipment you use. Get strong in the weight room with a variety of implements or ones you prefer, and then practice the separate skill of your sport. Where people go wrong is thinking they have to mimic the movements of their sport in the weight room thinking it will have a superior “transfer” effect to the field.

  • alex shaw says:

    Although it’s apparent that machines provide increases in functional strength, does anyone know if there has been a study the compares functional strength gains from machine based workouts and functional strength gains from barbell based free weight workouts? The results would be interesting, especially to see the differences in young/old populations.

    The application for sports teams would be huge as it would be a lot cheaper to have athletes train with barbells than machines. Also I would take a guess that machine training maybe more effect for an older generation if you take into account the time it takes for older people with poor motor control to learn the movements and the safety implications.

    Alex Shaw

  • Dunkman says:

    Great think piece. Thanks Chris. And Bret. In addition to all of this, I would have to think that the benefit of machines may also be highly variable, depending on the movement, the machine design, and how well the lifter fits the anthropometry the machine was built for.

  • Jamie Wolf says:

    Training should be about results period. Some machines provide a great stimulus for weak and inhibited muscles which in turn help correct muscle imbalances leading to improved joint stability, decreased pain and increased function! The best exercise programs are individually designed, properly progressed for each person and include a variety of exercises with machines, bands, bodyweight, cables, dumbbells, etc… Any so called functional exercise with bad form reinforces the cumulative injury cycle and dysfunction. This happens daily in gyms across America.

  • Big Russ says:

    Great information. I think the bigger issue with machines are they expensive and have limited function. The leg press machine in the picture is plate loaded. All you can do is leg press. A barbell still load plates can do multiple thing and a lot cheaper. So I get the research but the free weights are higher in value because of limitless function. So we just do argue that point that so much more can be done with a barbell, which is more functional who really knows.

  • tom t says:

    Ill address this specifically to the role of leg pressing in athletic populations.

    I don’t see in what condition a leg press is warranted in athletes other than in early stage rehab post lower limb surgery for slow joint loading reintegration and/or local muscle hypertrophy after a period of specific muscle atrophy.
    If an individual cant back squat then front squat, if he (or she) cant front squat then perform heavy single leg movements and some integrated truck work to compensate for the lack of trunk stimulus in the SL work, if he cant perform heavy single leg movements and trunk work then seriously give up.

    I get it that in this realm of performance science we want maximum results with minimum work involved, but using a machine based exercise that’s lazy coaching at best is plain negligent.

    There’s a range of additional points to Bret’s comments on machine exercises disadvantages you can also include:
    – increased muscle recruitment in free weight vs machines:
    http://www.ncbi.nlm.nih.gov/pubmed/19855308

    – The transition between the bottom of the movement into the concentric phase can often be observed as a lowering of the body or plate into relaxing and bouncing out of that hole where the athletes turn back on again during the ascent to complete the movement ( i know that not all will do this of course but many will).
    Theres a phase in athletics called the ammortization phase thats pretty bloody important. Ignore that at your peril. Continuing to strenghen the knee extensors at lockout once being helped out of hip flexion due to the collision of the machinery is nothing but fools gold. There arent many purely concentric pursuits out there.

    – Outside of published research, empirically we can see that the vast majority of leg press machines are limited in their range of motion capabilities depending on height and biomechanics of the individuals :
    = 45degree/hack machine/ sled type leg presses etc wont allow terminal hip extension ranges- a pretty crucial ROM to be strong in for any acceleration sports id say).
    = Other variations such as the lying leg press, while they do allow full hip extension at lock out will only allow hip flexion ranges under the condition of the pelvis typically leaving the bed of the leg press at the point where soft tissue restrictions wont allow maintenance of a neutral pelvis while keeping the flat of the lumbar spine against the bed. You can also see this happening on the 45 degree version also. Thats a worrying degree of shear force going on in the lower back there I suspect.
    Now if this was a squat the athlete or coach would pull sort of that pelvic rotation because the exercise becomes unstable and everyone knows how much everyone else is scared to death of a ‘butt-wink’ yet the leg press will allow this dysfunctional pattern because as the shoulders are fixed via the shouder pads and the foot plate is in a fixed movement plane therefore the movement becomes much less reliant on pelvic stability and efficient transfer of forces through the mid-rift.
    Disabling the pelvic control needed to perform a movement in order to maximise the forces exposed to the lower limbs? Sounds like a great recipe for massive muscle group recruitment/control and strength imbalances to me.
    The limiting point in the leg press tends to be the amount of force the legs can absorb and create, whereas the limit point in athletics tends to be how much force the body-system can absorb and create.

    Now some people will mention back injuries and long term limitations to squatting and there are alternatives as mentioned above which in my book that still makes the LP an invalid alternative.
    If individuals have lumbo-pelvic restrictions in their loading why on earth would you further increase the forces the legs can handle and at the same time ‘protect’ the trunk from the strength the legs are developing, bearing in mind when its time to compete in their sport the ground reaction forces once again will be limited by the forces the trunk can control from the legs.
    I dont know a land based sport where you can relax your middle and recruit your leg muscles at the same time, why dont we go further here and just stick to leg curling, knee extensions and back extentions just to really protect ourselves.?

    I may have a puristic view here but the benefits the LP seems to have aren’t actually benefits at all and in fact i am convinced the leg press will make athletes perform worse.

    The delusional act of sitting on your arse with the body fixed via the shoulders or back on a pad in order to expose the legs to huge forces to get strong in isolated restricted ranges that doesnt utilise a collection of stabilising and primer mover muscle groups that are necessary for human movement is mad isnt it?

    p.s
    – referring to the success performance programs have had in the NFL while using the leg press? come on, how many teams and crazy talented athletes in this sport have excelled in-spite of dumb training practice…the lists would be endless.
    – LP in rugby, only has notoriety because of the huge ego loads that can be used when big strong lads pack the machine to capacity and break 10dgrees at the knee. A confidence boost at best.
    – Also helps the generation-X to coach athletes whilst not having to learn the 101 of strength training coaching: squatting and deadlifting well.
    – Convenient when under resourced with quality coaches (above point).
    – Despite the macho sport, LP in rugby appeases a lot of soft trainers out there who play rugby well but cant stand the gym or the focus it entails. Easy option for these people.
    LP is a consequence of modern day rugby strength and conditioning practice not a success of it.
    – LP is functional if the task at hand is to be adept at LP performance. From the studies mentioned above there is no proof at all that the LP can increase athletic markers other than in the diseased, elderly or ‘young unathletic women’, that’s not a great population in order to validate the LP as an effective means to increase usable strength in trained athletes.

    Can we stop pissing on each others legs and telling each other its raining please? Its a terrible means to train athletes and should be used in the elderly/diseased/rehabilitators/bodybuilders where is does have merit.
    If you are coaching the LP in athletes then i hope youll be competing against mine.

    Note: Chris & Bret this is a wonderful resource you guys provide that I get much satisfaction from so don’t mind my personal gripe on the LP, its been a bug bear for years since i damaged my back leg pressing when I should of been taught how to squat instead as a youngster. We have bad blood.

    Anyway, many thanks for what you do.

    • Bret says:

      Hi Tom, the point wasn’t necessarily to say that athletes should be leg pressing, it was to address the claim that “the leg press isn’t functional at all.” Clearly it is. Is it as good as a squat, a deadlift, or a Bulgarian split squat? Most probably not. But I feel it still has value, as you mentioned for rehab, for elderly/diseased, and for bodybuilders. I also feel that it can help build strength off the ground with deadlifts – especially for guys like me who tend to use all hips and round their backs. In personal training, I’ll throw it in sometimes after the client has deadlifted (maybe I don’t want them squatting but I want a knee dominant exercise that allows for quick recovery), and sometimes it’s good in deload situations or with clients who have a nagging pain issue but the leg press is well tolerated (as a temporary work-around). I especially like the Cybex squat press, which just feels right in terms of load distribution on the hips and knees. But the point is that variety and a large arsenal is a good thing as it lends itself to more possibilities depending on the client and situation. Trust me, Chris and I both believe that squats, deadlifts, lunges/RFESS, and various posterior chain movements like hip thrusts and back extensions reign supreme, but science clearly shows that the leg press is much better for functional capacity than doing nothing at all. You made some good points about exercise biomechanics and considering the ranges of motion that are under load (and aren’t under load), and also that the leg press can be very dangerous if the lumbar spine isn’t taken into consideration and proper form isn’t stressed. I always appreciate well thought out comments, and I’m glad you enjoy Chris and my resource 🙂

  • Thanks for this, Chris and Bret! With all the gurus out there telling everyone that machines are the devil, it’s helpful to have an unbiased voice of reason.

  • Steven Sequoia says:

    I love the leg press and here’s why: I think it the best tool available to teach new lifters proper knee tracking and heel drive. They can look down the barrel of each shin and know instantly if they are or are not lined up, and it’s easier to correct when they aren’t worrying about balancing themselves at the same time. They can spend time getting stronger, getting pumped by setting new PR’s and it’s a great tool if ankle mobility is an issue. Once all of that is mastered, their squat training progresses much more quickly, because now, they only need to learn one or two new things instead of like ten.
    Plus, it’s important to know that it *can* be effective, even if not as much so as the squat, so on those days you just can’t to the squat rack (and we’ve all had those days) because it’s too busy, you can jump on The LP and not feel like your whole workout just got tanked. That is one lesson that I think it’s so important for clients to know: here are your priority (A) exercises, but if they aren’t available, don’t waste your valuable time waiting! Do B, C, or D instead. You’ll still hit what you need to hit for the day and just come back to it next time.

  • Martin says:

    Hi Bret
    The article argues that leg press training is good for you. I don’t think that is seriously disputed. However, the real question is weather time and effort spent on the leg press would not be better spent doing a squat or some other exercise. I know that there are other issues (eg safety) involved, but are there studies comparing the leg press to other exercises like squat variations?

    Martin

  • Jon Contos says:

    Hey Bret
    Just want to say that wolff’s law still apply’s to the leg press and possibly you might create this time under tension unique to the lift hyper trophy here we come!

  • Raptor says:

    I’ve always had a problem growing my quads… I can’t front squat due to flexibility issues, and I can’t really do narrow stance high bar squats because of the same thing – a lack of dorsiflexion (although that can be worked around).

    Maybe the leg press is a good idea in terms of quad development, since it has the advantage that the actual protagonist will work even more due to the better stability that the leg press provides vs. the squat.

    Obviously, I will use the leg press as an assistance exercise, so my main weapons will still be the high bar squat and the BSS (although in the BSS the glutes take over big time, even with a close stance and a lot of forward knee translation).

  • Miriam Hutchinson says:

    Bret thank you. I always look forward to receiving your emails/news.
    I can’t agree more with Steven Sequoia and Sam above. If the squat rack is busy which it usually is then why waste time, hit the leg press. Its excellent for knee tracking and heel drive. So true! I have a client with an ankle injury and even though she is fairly strong, I get her onto the leg press machine. As Sam said it doesn’t matter what type of equipment, its about getting strong and by using varied equipment to constantly challenge the muscles.
    Miriam

  • E says:

    Thank-you for this!

    During a sport injury I snapped my clavicle in half and required surgery. The sport I’m in mainly involves lower body strength, so I’ve been attempting to return to the sport only to find there are exercises I can’t do until my upper body strength is back to where it was (deadlifts, barbell squats, and heavy weight dumbbell lunges). There’s too big of a risk for muscular injury, so at the advice of a trainer, I went to the machines (leg press, hamstring curl, adductor, calf raises and abductor). I was met with a barrage of insults and “you’re wasting your time!” by fitness buddies when they saw which machines I was using. I decided to look into research on this, and this is one of the few articles I found that scientifically explains how I’m not wasting my time.

    I would love to be out on the floor squatting twice my weight with the bar right now, but the fact is the muscles in my shoulder can’t handle it. For now I’m happy with the machines and hope they’ll help me to get back in performing condition.

  • Tim Z. says:

    I’ve been using the leg press (among many other machines) for the last several months to get my 31-year-old body more ready for some double black ski runs out in Telluride. Not only has my strength improved, but via circuit training through machines, I’m confident that my stamina and heart strength/efficiency has improved as well. My point is that the results you identified in the studies and that are desired by many people in the gym can be achieved somewhat “directly” by strength training on machines and also what I’ll call “indirectly” (in a way) by the method and routine used to strength train. A workout, to a great extent, is multidimensional and will depend on more than just what equipment you are using. Love the article!

    I do think free weights are better in many cases for professional athletes in that they will work the tinier muscles that are used more for balance purposes. But for the sick, the elderly, and the common man, the increased risk of injury (and increased hassle of loading up bars and re-racking, etc.) from using free weights is not worth the increased strength in tiny and likely less critical [for everyday tasks] muscles. This paragraph is not in any way a rebuttal of your article — it is merely an elaboration of what you noted in your final “wrapping up” section. My hunch is that we’d agree on this.

  • TheManFromTaco says:

    Don’t use one of those horrible angled leg press machines. Use an old-school vertical leg press instead, being sure not to raise your glutes or back off of the cushion, in order to avoid strains or injuries. With the vertical leg press, you are actually bearing all of the weight yourself, whereas with the angled machine, the apparatus is supporting a large percentage of the weight.

  • Darren says:

    Tom – I’ve squatted 270kg and leg pressed 410kg (That’s all it would take). In my experience they both increase lower body strength and both exercises carry over to each-other. Ultimately they both improve general strength. Both are quad dominant exercises, both have risks. Both are useless as sports specific/functional exercises without training for the sport that you do.

    Leg presses are definitely easier to recover from than either squats or deadlifts. Single leg alternative’s are fine, but let’s be honest here, they’re useless at recruiting FT muscle fibres because they are unstable and you simply cannot overload the muscular system to the required load percentages to induce the desired training effect. Which basically is to increase the cross-sectional FT muscle fibre volume.

    You say that LP’s have a restricted movement pattern which can effect postural alignment of the hips, as does the squat. As I pointed out, both are quad dominant exercise, and without adequate inclusion of posterior chain exercises, lower cross syndrome is a risk when using either exercise as the primary lower body strength exercise.

    I also don’t see the fixed foot plate as a cause of a dysfunctional movement pattern. Both the LP and the squat are fixed foot position’s. In both cases movement occurs around the hip joint. Depth of ROM and muscle imbalances restricting mobility are more likely to cause butt wink in the A2G deep squat or openning up the lumbar spine in the LP.

    FYI, I’m not a believer in the A2G – it’s overrated, and as you have noticed butt wink is a risk factor that I simply do not see worth taking for anyone but an olympic lifter.

    As for the ego boost, this is prevalent in both squat and LP when restricted ROM is employed. You’ll find the reason why most people can LP far more than they can squat is down to the laws of physics. the 45 degree angle of the LP reduces the actual load being pushed by around 25% or so. It only appears that you are lifting a much greater load than you can squat. In reality it will be there or there about’s, the same as what you can actually squat.

    I personally predominantly back squat. However, if coming back from injury or wanting to train my legs but not fry my CNS, I will occasionally LP. That way I can still target FT muscle fibre recruitment.

    Oh, and doing a heavy ass LP, you don’t relax your abs. They’ll still forcibly contract to brace the body and fixate the hips. Heavy ass anything does recruit prime movers, synergist, stabilzer’s and fixator’s.

    So, all in all, I understand your points, but I don’t necessarily agree with your conclusions.

  • Leg Press remains one of my favorite exercises – not only because of its simplicity, but because of how it also trains you to handle extremely heavy weights in a relatively safe way. For a while, I did believe the bro science when it came to “functional strength” but I am quite self aware, and leg press did have some major benefits for me (mainly balance, which improved my dance skills 🙂 ).

    thank you for debunking this silly myth.

    – PheroJoe

  • BigZee says:

    I am a former competitive bodybuilder, I won several local shows (Class and overall) back in the late 90’s. I didn’t have the biggest upper body on stage but I was shredded with very thick legs. Needless to say Tom Platz was my hero growing up. Like Platz, I loved to Squat, my leg routine was built around it. But I also used the leg press quite a bit. I would say that leg pressing was my number 2 exercise for legs. I think the problem with the debate is that the leg press is often compared to the squat. This comparison is flawed. Squatting is the king of exercises and is a compound movement. The leg press should be viewed as an accessory movement for the quads. Many times in my own leg routine, i would leg press after completing my squats. Sometimes I would leg press a few light sets before squatting to get the blood flowing to the quads.

    As far as comparisons go, a fair comparisons could be the leg press to the hack squat or even leg extensions. the first thing that comes to mind is your probably going to do much more physical work on the leg press than you would a leg extension given the same set/ rep schemes. Although the hack squat is set up much the way the leg press is, I have seen a lot knee blow outs on the hack squat. I also saw a few knee blow outs on the leg extension. This is information is of course anecdotal, but it is my experience over the years. But why compare? All these exercises offer leg benefits if performed correctly, and they were all part of my leg routines at some point. My experience is from bodybuilding but, I also know accomplished power lifters that incorporated leg press into their own training.

    I think its myopic to dismiss the leg press as a beneficial leg exercise and it shouldn’t be compared to squats.

  • Magnus says:

    It works for eddie hall

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