Why can I Leg Press more than I Squat? ...Answered

Quite often through these boards I often see the question how come I can leg press much more than I can squat.

The answer is pretty simple and can be explained by 3 reasons:

(1) When using a typical sled type leg press you are in fact only moving the equivalent of 0.707 x weight because the leg press itself takes some of the weight.

(2) When squatting you are actaully squatting the weight of the load PLUS YOUR OWN BODYWEIGHT. When you leg press you sitting down you you don't actually have to lift your own weight.

(3) The leg press moves in a fixed path of motion, so stabilizers are less involved meaning you can shift more weight. The same principle applies when you consider the weight of DBs you can press compared to say benching on a smith machine.

I have worked out a rough formula to equate the two. I was bored walking home from the gym as my ipod ran out of battery.

Max Squat =~ (Stabilisation Factor x ((Max Leg Press x 0.707)) - Bodyweight

I found that the Stabilisation Factor will probably lie between 0.8 and 0.9 for most people, and will depend on body your body mechanics and how developed various stabilizer muscles are. For me it is approx 0.85.

Max Squat =~ (0.85 x (340 x 0.707)) - 85

In theory my max squat should be about 119 (its 115kg)

Or looking at it from the point of view of the amount you can leg press

Max Leg Press =~ ((Max Squat + Bodweight) / Stabilisation Factor) / 0.707

If anybody has any critique of this it would interesting to find out, or indeed if people work out their max theorised Leg Press from there Max Squat etc.

i can full range leg press over 800 lbs.

I can squat (with no wraps) 415.

Does that work with the formula?

I have seen guys who cant squat 315 load the entire leg press and get some reps in.

Another factor for leg press is tha tits really easy to do partial reps, knee bends really. I see it all the time.

Thank you. It should be common sense why you can leg press more than you can squat but I guess some people don't get it.

[QUOTE=dantheman999;365052471]i can full range leg press over 800 lbs.

I can squat (with no wraps) 415.

Does that work with the formula?

I have seen guys who cant squat 315 load the entire leg press and get some reps in.

Another factor for leg press is tha tits really easy to do partial reps, knee bends really. I see it all the time.[/QUOTE]

If you squat 415 and weigh approx 200 I would have guessed you could squat around 900-100. so it sorta works

[QUOTE=gingerguy21;365055251]If you squat 415 and weigh approx 200 I would have guessed you could squat around 900-100. so it sorta works[/QUOTE]

Sweeet. I really have no idea how much i can max leg press, i was just guessing. People dont really do 1RM leg presses do the?

[QUOTE=dantheman999;365056131]Sweeet. I really have no idea how much i can max leg press, i was just guessing. People dont really do 1RM leg presses do the?[/QUOTE]

I don't, I would'nt wanna find out by going 10kg over and getting stuck under it. I just work it out using a 1RM calc.

Are we assuming a 90 deg. leg press here? If not you would have to factor in the angle also I believe.

Pretty good equation you came up with. Comes out pretty accurate for me too. I assumed I can squat 145kg for atleast 1 rep (I can do 140 for 3 reps), and I have leg pressed 340kg for 6 reps on the leg press previously. The equation said I could lift 404kg for 1 rep. ]

However I know some guys who can squat over 400lbs but struggle on the leg press.

[QUOTE=Teledin;365078311]Are we assuming a 90 deg. leg press here? If not you would have to factor in the angle also I believe.

Pretty good equation you came up with. Comes out pretty accurate for me too. I assumed I can squat 145kg for atleast 1 rep (I can do 140 for 3 reps), and I have leg pressed 340kg for 6 reps on the leg press previously. The equation said I could lift 404kg for 1 rep. ]

However I know some guys who can squat over 400lbs but struggle on the leg press.[/QUOTE]

I think he is talking about hte angled one. Thats why he put in the .707, i think anyway.

I wrote this up a while a go explaining the short falls of the Leg Press. You might like it OP:

Why the Leg Press Sucks and How to Fix it! Video & Pictures

[url]http://forum.bodybuilding.com/showthread.php?t=113484421&highlight=bands[/url]

leg press is a damm machine, and is in a different postion than a squat

[QUOTE=dantheman999;365078891]I think he is talking about hte angled one. Thats why he put in the .707, i think anyway.[/QUOTE]Yes, the effective work done on a 45 degree inclined leg press will be .707x the actual weight loaded. This will, of course, change for a 90 and 60 degree leg press.

Your math is still off. My best ever deep squat was 585 (I weighed around 250), but I've leg pressed around 2K for 25 reps, knees to chest. 1400=/= 585+250

[QUOTE=JasonDB;365201241]Your math is still off. My best ever deep squat was 585 (I weighed around 250), but I've leg pressed around 2K for 25 reps, knees to chest. 1400=/= 585+250[/QUOTE]

25 reps at 2000lbs, knees to chest?

Ronnie Coleman leg pressed 2250 for about eight (I can't remember) with a pretty small ROM.

Sorry but I don't buy it.

[QUOTE=flangmasterj;365228841]25 reps at 2000lbs, knees to chest?

Ronnie Coleman leg pressed 2250 for about eight (I can't remember) with a pretty small ROM.

Sorry but I don't buy it.[/QUOTE]

You don't have to maybe I was on a slide with less resistance. Maybe Ronnie is capable of a lot more. I mentioned in another thread that given the estimates I've seen from my own squat to leg press ratios, as well as those of other guys I've known who leg press a lot, that Ronnie could probably leg press well over 3K if anyone made a slide for him to do it on. I've seen 115 lbs women leg press 800 lbs knees to chest. Anyone who can squat 405 atg, can most definatley leg press 1500-1600 for reps if they spent a month working on it twice a week. I bet Ronnie could do 3k+ on the leg press for 10 reps if he had the equipment available, and he had a little time to get used to the weight on the slide. He only works 2200 because that is what is available, and he probably doesn't normally work 20+ reps for legs.

[QUOTE=dantheman999;365052471]i can full range leg press over 800 lbs.
I can squat (with no wraps) 415.[/QUOTE]

Now that's odd.

I could leg press 4x the weight of my squat (comparing my 10RM). I think my leg press is alright but my squat is weak. Mainly because I had a weak lower back.

Shouldn't it be 0.5 for 45 degree leg press?

What's the point of leg pressing with your knees hitting your chest? A little bit more work on the glutes? It's not the right way to do it.

[QUOTE=sirbobmontgomery;365324431]What's the point of leg pressing with your knees hitting your chest? A little bit more work on the glutes? It's not the right way to do it.[/QUOTE]
How are you supposed to do it then?

Pretty damn sure it's knees to chest, or really close to your chest.

[QUOTE=sirbobmontgomery;365324431]What's the point of leg pressing with your knees hitting your chest? A little bit more work on the glutes? It's not the right way to do it.[/QUOTE]
Agreed.

I do not believe in making an angle lesser than 90 degrees.

It's supposed to be 90 degrees.

[QUOTE=redbinder;365275091]Shouldn't it be 0.5 for 45 degree leg press?[/QUOTE]

No, because the component of the weight acting down the lift to your legs is the sine of 45Degrees, or cosine for that matter, which is 0.707.

Also, if one guy said i can do 6 reps at 200kg down to my chest, while another says i can do 6 reps to 90 degrees, who would you say is stronger? I suppose it also depends on user preference.
I prefer to go ass to grass with squats and knees to chest with legpress.

[QUOTE=gingerguy21;365050671]
Max Leg Press =~ ((Max Squat + Bodweight) / Stabilisation Factor) / 0.707

If anybody has any critique of this it would interesting to find out, or indeed if people work out their max theorised Leg Press from there Max Squat etc.[/QUOTE]

Nice simple formula; I like the way you incorporate a 'fudge factor' in to account for some slop. :D Some observations:

1) Our full body weight isn't being squatted when we do squats. Weight below the knees is nearly negligible and weight from knees to hips is lifted in a lever movement. Not that this decrease in body mass is worth taking into account for a simple equation (it can be incorporated into the stabilization factor).

2) I instinctively feel like the equation will work better for squat->leg press calculations rather than vice versa. I say this mainly for people who don't squat (the weak) and would have a terribly low stabilization factor.

3) ROM on these has to be crucial. People that squat to parallel will likely have a different result from the equation than those who squat ATG (unless depth on the leg press correlates).

4) I think an interesting way of using this could be to calculate your 'stabilization factor', it's the only variable in your equation that can't be determined directly. If you find a max on squat and leg press (5RM, 10RM?), you could get this number. Not that it would do you too much good..maybe a new e-stat?

[QUOTE=JasonDB;365201241]Your math is still off. My best ever deep squat was 585 (I weighed around 250), but I've leg pressed around 2K for 25 reps, knees to chest. 1400=/= 585+250[/QUOTE]

5) For heavier weights, the equation may break down. A heavy compound movement (squats) becomes more difficult to continue to add weight to than a more isolated one (leg press).

[QUOTE=gingerguy21;365050671]Quite often through these boards I often see the question how come I can leg press much more than I can squat.

[/QUOTE]

TBH I've never seen that question asked. I could be wrong though...

[QUOTE=fas52b;365376251]
5) For heavier weights, the equation may break down. A heavy compound movement (squats) becomes more difficult to continue to add weight to than a more isolated one (leg press).[/QUOTE]

Right, I am thinking this formula is fine for people who are a bit weaker, but I've noticed it becomes very inaccurate for men who can deep squat over 315 lbs and women over 200 ish. I've had a friend who could squat 315x6 but do full ROM leg presses with WELL over 1k, and a woman with a 185 max squat do 800 lbs on the leg press. For stronger individuals I would say the leg press, if they spend some time working on it (I did for about 6 months because another bodybuilder convinced me doing heavy squats all the time would thicken my waistline up so I stopped squating for 6 months because of this rediculous advice and started leg pressing twice a week and got up to 2k for my worksets before just going back to squats) is something in the range of 3.5-4.5x their squat.

In any event I feel the squat is a better movement having used both extremely heavy squats and leg presses seperately as a primary mass builder. My thigh development didn't signifigantly improve when I dropped squats for heavy leg presses, however it did once I stopped leg pressing and went back to squats.

[QUOTE=InsanityDefined;365326871]How are you supposed to do it then?

Pretty damn sure it's knees to chest, or really close to your chest.[/QUOTE]

Also, when your knees come to your chest, your butt comes off of the pad which creates a round in your back which is risk to injury and poor posture.