I recently read the following message from a friend of mine:
400 kilos for 8 reps on the leg press!!!!
I’m getting so much stronger and leaner!
For those of you who need a weights and measures conversion, 400 kg is 880lbs.
That’s almost 900 pounds of leg strength…or is it?
That message came from a particularly big burley Englishman. He looks like a man mountain and he is a really nice chap but I’ll let you in on a secret. He can’t squat.
Don’t get me wrong – I’m not saying the guy is a weakling but I know for a fact there is no way he can back squat with full ass to the grass range of motion even 30% of that leg press weight.
Machine weight systems can easily give you a false perception of reality, in this case of the leg press let’s have a look at why:
1- You are seated. This means that the movement is supported by a back rest meaning there is far less midline stability involved. In a squat, you support yourself with your midsection muscles. Front and back. Without this support you’d snap in half. The seated position is fantastic if you need to work your legs because and cannot squat due to injury. You will get some nice hypertrophy (muscle growth) going on and if you’re a bodybuilder you can argue that the movement isolates specific muscles better so if that’s the case keep doing it! But due to the limitations of being in the seated position, growth and strength gains are limited (see 3).
2- You press the weight through a railed system so the path of travel is singular. There is only ever one way to go and it’s guided so balance is never really an issue. This doesn’t necessarily mean you won’t know which side is stronger as you can do single leg movements on a leg press but it does mean that because the movement is guided you can press more.
With the squat you have to balance the weight through your legs yourself. You need to have co-ordination on the squat that simply is not required on the leg press.
3-Experiments have shown that you get more muscular growth with the squat than the leg press (James et al)
4-You don’t use hip flexors in nearly the same way you do in the squat. This is illustrated by this nice story I read a few years ago (the weights are all in KG so do the math yourself):
“This shorter more muscular guy who was leg pressing 450 asked me why I was only using 135 for my squats. I challenged him to try just one set with 135. (He was all warmed up from his leg presses, so I was pretty sure he wouldn’t get hurt.) He said, “Heh-heh, no sweat, man.” I pointed out to him that I was using the light weight because I had just changed my form to go “in the hole” and then challenged him to try it. He did. He went down too fast and without enough tension or control. He didn’t get hurt, but he couldn’t get out of the hole! And there’s a simple reason why: He didn’t have the hip flexors to do so. Leg presses, leg extensions and leg curls do not work the hip flexors like squats and deadlifts do. The man was truly embarrassed, apologized profusely and later shook my hand in the locker room and said, “you’re a strong dude, man.” Well, I’m not, I just have highly developed hip flexors.”- Pumping Iron,John O.
5-The knee angle throughout the leg press range of motion makes the movement far easier than squatting. On a leg press machines the angle can be up to 25 degrees less meaning less work is done on each lift so you can lift more weight. That makes you think you’re doing more, when in reality you’re not. A bit like regularly only running long distances to get fit might make you feel good but won’t develop all round fitness.
6-I don’t go about my life sitting down and pressing things with my legs. In that respect you can argue that the seated press is not in any way functional, unless you drive a car with very, very heavy clutch, accelerator or brake pedal.
I could go on but you get the point.
Again, don’t get me wrong! I think leg press machines are great. The history of them is really nice.
The first one was invented by a famous strongman Siegmund Klein. He weighed less than 150lbs but could strict pressing 229lbs and he could back squat 300lbs for reps.
I can tell you for a fact that our friend Sig didn’t get his strength from his invention, he got his strength from doing compound barbell, dumbell and kettlebell full body movements. The machine just helped things a little.
You can read more about Sig Klein here:
Leg Press machines as rehab tools are fantastic. They are a pretty good deadlift assit as well. They are actually quite hard to use correctly with heavy weight as you have to keep your butt on the seat padding which is hardly ever done. This isn’t so easy if you’re a gentleman with gentleman parts that can get in the way.
You won’t find a leg press machine at CrossFit Brit. I’d rather spend the $4000 a decent one costs on barbells and bumper plates, which you can do far more with.
I’d rather see front squats, back squats, overhead squats, deadlifts, cleans, snatches and many other movements done instead to develop athletic performance. They turn boys into men and empower women to achieve excellence.
On a side note, just to put the leg press into perspective, former US Secretary of State Madeleine Albright has gone on record saying that she can leg press over 400lbs. She is 76.