Keiser vs. Free Weights/barbell

[Pr199020]

Now I'm not a complete newbie. But for all intents and purposes I am one. I'm starting on my fitness journey to a healthy lifestyle and hopefully a great body to go with it. Anyway I just have a question of mechanics that I don't understand. So, basically I can squat on the keiser squat ,which uses air as a form of resistance therefore decreasing momentum to maybe not zero but close to it about 280lbs for 3 sets of 10 struggling on maybe the last 3-4reps.

On the the normal barbell squat I can barely do 115lbs?? for 2 sets of 12. Now maybe there are other factors that I'm not fully aware of that contribute to the discrepancy. I know that the barbell no matter how far down or high I put the barbell my back just hurts as well as the I feel like my arms are being stretched that sometimes they get a cramp in the shoulder are just from holding the bar the way I do. I tried putting the pads but that doesn't work for me.

I thought that initially maybe my back couldn't support the weight but my legs were strong enough that they could go on if my back could keep up although I have fairly skinny legs. What made me change my mind was that I was doing Keiser leg presses which are horizontal and I could press 370lbs for 3sets 12reps.
But once I get to a weighted machine leg press. I can barely do 225 for 10 reps for one set.

My question is what's going on. Am I not pushing myself hard enough? Or are the way the air resistance is set up you divid the weight by 2? Or am I being handicapped by the keiser machines? Although, I don't see how at least on the leg press. As much as my ego is cool with these high weights there is an asterisk there because more than likely those numbers are way inflated. I would like to incorporate the barbell because clearly I can't squat much. But I don't know if that is a factor of leg strength or my back strength/flexibility. Because if it is I don't really know how to fix it. I'm 5'8 23 years old. Always been athletic sports all my life but never had the "athletic" body i.e. abs, low body fat, visible muscle, like my peers. Anyway any advice or thoughts would be helpful.

[cmarti063]

Get a copy of Starting Strength, read it, and do what it says. From this post, it's clear you have much to learn.

http://www.amazon.com/gp/aw/d/098252...&robot_redir=1

[Wildtim]

The air resistance is nothing like real weight, or even a leg press weight. What you can do on that machine doesn't translate to anything at all.

doing what is in the above post would be a really good idea.

[KBKB]

The air resistance is nothing like real weight, or even a leg press weight. What you can do on that machine doesn't translate to anything at all.

Agreed. And, in general, it's difficult/meaningless to compare weight on one machine to another of the same type unless the machines are identical with regard to mechanical advantage, ergonomics, etc.

[TheScrawnyDude]

You cannot compare weights from machine to machine. Each machine is going to behave differently. Perhaps the mechanical levers are different size, perhaps the resistance a bearing produces is different, etc, etc, etc. So while moving from 280 lbs to 300 lbs on a single machine means you are getting stronger, pushing 280lb on one machine has zero correlation to how much you are going to be able to push on another machine. Even machines of the same design can apply different forces due to wear and other factors. So 280lb on leg machine A may not produce the same resistance as 280lb on machine B even if it is the same type and brand machine, and it certainly isn't going to have any correlation to another type of machine all together.

In the same way, weights on machines will have zero correlation to how much free weight you can push. So pushing 280lb in a keiser squat machine has zero correlation to the amount of weight you can push in a free weight squat. Any free weight movement is going to be a compound movement - meaning you are using lots of different muscles. That's why free weights are considered by far the best way to strengthen your body. Machines are designed to isolate and strengthen individual muscles. Free weights will end up strengthening lots of muscles during each movement and more accurately mimic real life scenarios. I've never seen a situation in real life where being strong in a single muscle was an advantage. Usually in real life you are called upon to lift and move heavy things - movements that require the use of a lot of muscle groups. This is what working with free weights mimics, machines don't offer this same advantage.

[Skyaura]

You cannot compare weights from machine to machine. Each machine is going to behave differently. Perhaps the mechanical levers are different size, perhaps the resistance a bearing produces is different, etc, etc, etc. So while moving from 280 lbs to 300 lbs on a single machine means you are getting stronger, pushing 280lb on one machine has zero correlation to how much you are going to be able to push on another machine. Even machines of the same design can apply different forces due to wear and other factors. So 280lb on leg machine A may not produce the same resistance as 280lb on machine B even if it is the same type and brand machine, and it certainly isn't going to have any correlation to another type of machine all together.

In the same way, weights on machines will have zero correlation to how much free weight you can push. So pushing 280lb in a keiser squat machine has zero correlation to the amount of weight you can push in a free weight squat. Any free weight movement is going to be a compound movement - meaning you are using lots of different muscles. That's why free weights are considered by far the best way to strengthen your body. Machines are designed to isolate and strengthen individual muscles. Free weights will end up strengthening lots of muscles during each movement and more accurately mimic real life scenarios. I've never seen a situation in real life where being strong in a single muscle was an advantage. Usually in real life you are called upon to lift and move heavy things - movements that require the use of a lot of muscle groups. This is what working with free weights mimics, machines don't offer this same advantage.

TheScrawnyDude

A few things about your post are incorrect. First "any free weight movement is going to be a compound exercise" is not a true statement. A bicep curl with a dumbbell is an isolation exercise done with a free weight. The Keiser Air300 Squat is a machine that is a compound exercise because it is a multi-joint exercise that involves the hip, knee and ankle joints. It is going to hit more than one muscle group

Not all machines are "designed to isolate and strengthen individual muscles." For example a "Jammer" machine is designed for an explosive movement that involves the whole body. A functional trainer can be used for hundreds of exercises some of them isolation and some of them compound movements. Now I am in agreement that generally speaking, compound exercises, performed using free weights are the way to go. Squats, Deadlifts, Pullups, Military Press, Power Cleans etc are all wonderful exercises and you will get much more bang for your buck doing these instead of a leg curl or bicep curl. But machines have their place.

Keiser equipment, particularly the Air 300 Squat is used in many athletic facilities because you can do explosive squats more safely with less impact than a free weight squat. Not saying it is a better exercise than a traditional barbell squat, but to an athletic trainer who is trying to increase an athlete's strength while lessening the odds of injury it is a good choice (particularly in season). Also, the free weight/ compound weight argument more accurately mimics "real life" can be taken to far.

For example, you can do deadlifts until the cows come home, but it will not make you throw a baseball better. A deadlift can help with increasing the speed a player can throw a baseball, but to do that particular skill correctly involves learning the proper mechanics in throwing a baseball and practicing that skill. And of course with better mechanics the speed and distance a baseball can be thrown by a player will increase without lifting a weight. The takeaway is that if you want to do learn a certain skill it involves learning and practicing that skill. A Bench Press is not going to help a person shoot a pistol more accurately. A squat is not going to help someone learn to play the guitar better. These are all "real life scenarios."

I am in agreement that what one lifts on a machine has zero correlation to a free weight exercise. I am in agreement to with what others suggested that "Starting Strength" by Mark Rippetoe is a very good choice for a novice getting into weight lifting.

[Synthetickiller]

Just going to leave this here.



Some good info here. There's 5 parts: http://www.youtube.com/playlist?list=PLD7BE939BB32B4CAB