Leverage Conversion to Free Weight

[Leverage]

Hello,

I own a Powertec Multipress Leverage Workbench, and I've been wondering just how closely leverage translates to lifts using free weights. I asked a Powertec representative this question and was given the following formula:

Leverage weight (L) minus 10% + 18 lbs (which is the weight of the arm).

So: (L)(.9) + 18 = amount you can actually do with free weights.

Therefore, if you max out at 315 lbs in leverage weight with the Powertec, then you can approximately do 301.5 lbs in free weights.

(315)(.9) + 18 = 301.5


This sounded about right to me, but a friend of mine had an experience that would suggest that the equation given to me is pretty far off. To give you some background, he has the exact same setup as me. He is able to do 225 (converted from 230; 230*.9 +18 = 225) 16 times on his Powertec. However, today at the gym using only free weights, he was only able to lift 225 four times. Four times! Obviously, that was disappointing to us both and left us wondering exactly what is an accurate conversion for leverage systems in general and the Powertec in particular.


Can some of you leverage owners, especially Powertec owners, give me some feedback on the conversion issue? I would really like to have some accuracy when measuring my strength gains.

Please no debates about leverage versus free weights; let's just stick to the topic.

Thank you for any helpful feedback!

[Dinotrainer]

That "Powertec representative" doesn't know **** from shinola. There is no "conversion" from leverage to free weights, as proved by you and your friends experiences. Sure, you could mathematically figure out how much extra force can be applied using levers, but you can't factor in the "human" thats actually supplying the force. Some people are MONSTERS on leverage equipment, yet cant lift anywhere near the same once the lever arm is taken out of the equation.

[Skidmarx]

I think the problem with leverage is it stabilizes the weight for you, so all your effort is the movement. With free weights, more effort is involved keeping the bar position right, so it's harder to do. That should tell you something right there.

[need2eat]

Dinotrainer nailed it.

My favorite part of going to the gym was doing leverage equipment on days I felt down...instant strongman.

Leverage equipment isnt ideal, as you take out the need for stabilizer muscles, which isnt good for strength training, hypertrophy on the other hand, might not be as bad, as your objective is to develop the shape of your body, although, the more muscle you can stimulate to grow, the better, since you already have the equipment, focus on progressively adding weight and you should be fine. Just dont get depressed when you test yourself on freeweights.


Another thing, dont judge your freewight ability the first time out. You still have to in a sense relearn the movement. While leverage bench for example, is basically the same as free weight bar bench, in many ways, its not, its a new movement to the body, so a brief learning experience (few freeweight workouts) is expected.

[Leverage]

Surely a formula can be constructed for a "specific" leverage machine (meaning one accounts for the design differences between the various brands) to provide a decent estimate for the conversion. It won't be perfect or a 100% accurate translation, as some factors cannot be addressed (i.e. stabilizer muscles).


But that should hardly make a decent estimate an impossibility. It's merely physics.


So if anyone who owns a leverage machine and has compared the results with free weights, please add your thoughts.

[Dinotrainer]

Surely a formula can be constructed for a "specific" leverage machine (meaning one accounts for the design differences between the various brands) to provide a decent estimate for the conversion. It won't be perfect or a 100% accurate translation, as some factors cannot be addressed (i.e. stabilizer muscles).


But that should hardly make a decent estimate an impossibility. It's merely physics.


So if anyone who owns a leverage machine and has compared the results with free weights, please add your thoughts.

I didn't "armchair theorize" when I gave the info in my last post, I've actually owned and used a PowerTec WBLS side by side with a Power rack. The info given to you was based on mine, and several other peoples experiences (all different) on the rack vs. machine. Typically, the less strength and/or experience you have, the more subtle will be the difference. What YOU need to do in this case is take all the baseline data for YOURSELF on your leverage machine, then go try it in a rack. Record all YOUR numbers, and then periodically go back and do the same thing again (for whatever reason you feel that you need to do this). Or.......if you're really interested in what you can actually lift with "free weights", maybe look into getting and TRAINING with a rack ......it's really that simple, no "equation" necessary

[C Man]

Why do you want to know what the 'conversion' is? Are you using free weights at a gym as well as your leverage unit? You haven't been clear on that.

[Labrador]

The thing with leverage gyms is that the grips are farther away from the joint than the weight, so you get a lever effect. Your arms/legs move over a greater distance than the weight, so it appears much lighter. e.g. If the weight is halfway between the joint and the grip, only half the force is needed.

[PopeyeFAFL]

Hello,

I own a Powertec Multipress Leverage Workbench, and I've been wondering just how closely leverage translates to lifts using free weights. I asked a Powertec representative this question and was given the following formula:

Leverage weight (L) minus 10% + 18 lbs (which is the weight of the arm).

So: (L)(.9) + 18 = amount you can actually do with free weights.

Therefore, if you max out at 315 lbs in leverage weight with the Powertec, then you can approximately do 301.5 lbs in free weights.

(315)(.9) + 18 = 301.5


This sounded about right to me, but a friend of mine had an experience that would suggest that the equation given to me is pretty far off. To give you some background, he has the exact same setup as me. He is able to do 225 (converted from 230; 230*.9 +18 = 225) 16 times on his Powertec. However, today at the gym using only free weights, he was only able to lift 225 four times. Four times! Obviously, that was disappointing to us both and left us wondering exactly what is an accurate conversion for leverage systems in general and the Powertec in particular.


Can some of you leverage owners, especially Powertec owners, give me some feedback on the conversion issue? I would really like to have some accuracy when measuring my strength gains.

Please no debates about leverage versus free weights; let's just stick to the topic.

Thank you for any helpful feedback!

Not sure what a Powertec Multipress Leverage Workbench look like, but I own a WB-LS, and I did post this:

http://forum.bodybuilding.com/showth...ighlight=ratio

Here an abstract:

Knowing that the distance from the pivot to the weight location axis is roughly 27 inches and the distance from the same pivot to the handle (where your hand input the force) is roughly 39 inches, the ratio is then 27/39 = 70% or if you like, if you put 390 lbs on the weight axis, you will need only 270 lbs of force to lift it (in horizontal position, since that force required will vary all along the motion). And that does not include the "U" shape (37.5 lbs) that you are also lifting, with some moment arm.

So I think, that that Powertec representative is full of it ****.

[Doug J]

Popeye has it about right. The physics should be around 70% if you are used to working out with free weights. My experience was that I could only do 60-65% when I went from leverage to using free weights. Since I was accustomed to using leverage, stabilizer muscles were weak and it was very awkward benching free weights.

[PopeyeFAFL]

Popeye has it about right. The physics should be around 70% if you are used to working out with free weights. My experience was that I could only do 60-65% when I went from leverage to using free weights. Since I was accustomed to using leverage, stabilizer muscles were weak and it was very awkward benching free weights.

So for me, the best of both world is:

Leverage gym for bench, squat, lat pull down, etc., where you are not afraid of going to failure (safety of a gym, no spotter, etc.) + dumbbells exercises with some heavy weight to work your stabilizer muscles.

I think, this should work (not for everybody, perhaps, but for those, who give up squat, or heavy bench, because of their fear of injury in a power cage).

[Dinotrainer]

.....Another thing, dont judge your freewight ability the first time out. You still have to in a sense relearn the movement. While leverage bench for example, is basically the same as free weight bar bench, in many ways, its not, its a new movement to the body, so a brief learning experience (few freeweight workouts) is expected.

Very true.....

[No1ustad]

sorry to revive an old thread, but i found it valuable.

so the consensus pretty much says, (leverage weight*.7) + 37.5 to get a decent guesstimate of freeweight? obviously all variables won't be able to be accounted for.

[Squeebo]

sorry to revive an old thread, but i found it valuable.

so the consensus pretty much says, (leverage weight*.7) + 37.5 to get a decent guesstimate of freeweight? obviously all variables won't be able to be accounted for.

No. Being able to move a freeweight bar where you want it accounts for a large part of how much you can lift. You can do the math on the force applied, but the reason there's no real-world conversion is you don't know how much a given person has lifted freeweights before and how well he'll be able to balance a bar in a given position and range of motion. Freeweight lifting uses more muscles, and if he hasn't used those muscles before, then good luck.

Why do you want to know?

[FatGymRat]

The formulas are all bunk. Everyone will have a different percentage based on how developed their stabilizing muscles are developed and how clean their technique is.

Making any empirical statement would be like saying that since I can bench 250 (x) times with a barbell, I should be able to bench 125 lb dumbbells for the same number of reps, or saying that there is an absolute ratio for the difference in these movements.

Any ratios stated are going to be anecdotal evidence based on personal experience or a small cross section of people. Either that or it's purely wild speculation.

Just try to work in some freeweights with your leverage work.

[qaz123]

just improve over time on that exercise don't worry what the conversion is who really cares...

[thedickus]

just improve over time on that exercise don't worry what the conversion is who really cares...

Best answer to this I've heard yet. Who cares. It's a different exercise than a b/bell press. If your weights and/or reps go up then you're improving and given all other factors are in order, i.e. rest, diet, etc, then hypertrophy should occur. And in the long run isn't that what bodybuilders are after?

[Squeebo]

I'd still like to know why people want to know the conversion. There's a lot of ego lifting going on, and I suspect most are just out to tell their friends how much they can lift freeweight or are planning to do freeweights soon and don't want to look weak by starting too low. A good reason would be that they're planning on how much weight to buy, but I never hear that explanation.

[yankeemarko1]

I'd still like to know why people want to know the conversion. There's a lot of ego lifting going on, and I suspect most are just out to tell their friends how much they can lift freeweight or are planning to do freeweights soon and don't want to look weak by starting too low. A good reason would be that they're planning on how much weight to buy, but I never hear that explanation.

^^^^This. I have a WB-LS. I don't care how it translates. I make gains weekly. That is all that matters. Repped.

[FatGymRat]

I'd still like to know why people want to know the conversion. There's a lot of ego lifting going on, and I suspect most are just out to tell their friends how much they can lift freeweight or are planning to do freeweights soon and don't want to look weak by starting too low. A good reason would be that they're planning on how much weight to buy, but I never hear that explanation.

A wild guess, but maybe he's trying to compare his 1RM numbers with someone.

[Squeebo]

Agree. I say keep the formula simple. Use a barbell or dumbbells in a leverage gym, problem solved. See pics. and video below. This is only a prototype of my concept of a free range of motion leverage home gym. It allows barbells or dumbbells to be lifted freely using all your stabelizing muscles.
http://www.youtube.com/watch?v=8Zf6VQFXjQ4

That's interesting. Keep in mind that some people will want to grip a bar right where the leverage arm attachments do, so it would need to be adjustable.

[thedickus]

Agree. I say keep the formula simple. Use a barbell or dumbbells in a leverage gym, problem solved. See pics. and video below. This is only a prototype of my concept of a free range of motion leverage home gym. It allows barbells or dumbbells to be lifted freely using all your stabelizing muscles.
http://www.youtube.com/watch?v=8Zf6VQFXjQ4

Seriously dude, 40 posts and only 1 of them has offered any advice and wasn't about you advertising equipment you're making.

[yitmy]

All very true, But not all leverage was created equall. For example a hybrid leverage such as the power spot concept home gym adresses these issues in that the user has to stabilize the weights. The power spot forces the lifter to use stabilizing muscles whether using a barbell or dumbbell. conventional Leverage arms pivot in an arc motion forcing the user to follow the machines range of motion fixed in all directions. I personally designed the power spot to incorporate safety, lifting dumbbells or barbell to failure and still enabling a full range of motion. fairly simple formula here, if some choose not to use a power rack and insist on leverage gym the power spot might be an alternative if it was available, but it's not yet. See pics. and video link in my above post.

The Power Spot is a nice piece of equipment but its a self spotting safety system and not a leverage based system. Unclear of the connection here.

Leverage systems tend to work good at increasing power or force through a predesigned vector. Freeweight machines like leg machines also use the same concept. Use of freeweights for multijoint muscles say Squat can be more effective for there are numerous forces occurring through the ROM of each particular joint/muscle at certain times. Unfortunately due to the fixed vector the feeling is different with leverage machines. That said you can still develop strength and muscle tissue but I have not seen any standardized research saying which system is better(usually research is paid for by the equipment companies and can lead to biased results-if they do not like the results then they just toss it out for they are paying for it). Humans as you may know are unique so testing unique specimens who do not react the same way to particular stimuli is of limited value at best.

I am unclear due to the multiple forces that occur through the range of motion with leverage vs freeweight on how you can come up with some value as to how one compares to another. Remember leverage is work through a predesigned force angle where as freeweight exercises outside machines there are numerous forces occurring which are very difficult to measure as they occur. So any number you can come up with is sadly not a true measure of how one relates to another. For example use of a Bowflex is not related to use of freeweights or leverage. As you increase the resistance of your particular system does not translate out to other systems out there just to what you are using.

[FatGymRat]

The formulas are all bunk. Everyone will have a different percentage based on how developed their stabilizing muscles are developed and how clean their technique is.

Making any empirical statement would be like saying that since I can bench 250 (x) times with a barbell, I should be able to bench 125 lb dumbbells for the same number of reps, or saying that there is an absolute ratio for the difference in these movements.

Any ratios stated are going to be anecdotal evidence based on personal experience or a small cross section of people. Either that or it's purely wild speculation.

Just try to work in some freeweights with your leverage work.

Agree. I say keep the formula simple. Use a barbell or dumbbells in a leverage gym, problem solved. See pics. and video below. This is only a prototype of my concept of a free range of motion leverage home gym. It allows barbells or dumbbells to be lifted freely using all your stabelizing muscles.
http://www.youtube.com/watch?v=8Zf6VQFXjQ4

Don't key off my post to segue into your product shill....

Doesn't this site have a rule that product reps have to be identify themselves in their sig so te other members know that they may be reading a pitch?? I am not saying you need to wear the scarlet letter ("the S is for shill") but at least show some tact and announce yourself.

Also, if you're going to shill something, it should at least be something that people can buy.
Not that I am personally interested. It looks like a perfect solution... to a non-existent problem.

Negged for quoting my post and bastardizing my statement to make an advertisement for your non-existent product. If you want a setup man for your online infomercial thread, you should hire one.

[animalfan]

Seriously dude, 40 posts and only 1 of them has offered any advice and wasn't about you advertising equipment you're making.

yes.

Thanks? I'm not sure how the 40 posts factor into the equation of the first post on this thread or the fact that you forgot to mention my rep power =o . How did you get so sidetracked from the original topic leverage conversion formula . By the way I'm not making and have never offered my concepts for sale. I'm only trying to explore the bridge between power racks and fixed leverage gym equipment to see if my concepts might offer alternatives at a price point that might offer more product for the buck. By the way my power spot home gym does have lever arms that hold weights and does fall into this discussion under the equipment forum.

i'll be honest, i didn't just review your previous posts. but the only time i've ever noticed you posting is when there are links to your lever-arm-spotter-system-thing. i do recall your first post here (i'm pretty sure it was your first) when you claimed that you were browsing youtube and came across this "very interesting idea".

i have been resisting my urge to neg you for a while. please, if you are going to post spam to your invention, try to share some other knowledge with us in between pics and links to your product.

thank you very much.

[HardKore79]

Someone needs to go and read the forum rules... Also negged for repeated advertising on here.

[thedickus]

Thanks? I'm not sure how the 40 posts factor into the equation of the first post on this thread or the fact that you forgot to mention my rep power =o . How did you get so sidetracked from the original topic leverage conversion formula . By the way I'm not making and have never offered my concepts for sale. I'm only trying to explore the bridge between power racks and fixed leverage gym equipment to see if my concepts might offer alternatives at a price point that might offer more product for the buck. By the way my power spot home gym does have lever arms that hold weights and does fall into this discussion under the equipment forum.

There are several extremely helpful people on this forum who actually work in the fitness sales industry. Never once have I heard them trying to sell any of their products. They offer advice as to the quality of the equipment in question and/or recommended price. You've said in past threads that you're trying to market your invention. Quit tyring to use this board as your own marketing focus group and go peddle your crap elsewhere. I've never called anyone out on this board before. Congratulations, you're the first.

[yitmy]

Thanks, the power spot is technically a leverage gym in that it has pivoting arms that support a weight mass. The only difference is that a power spot does not have the limitation of a fixed vector it enables the user to follow their natural range of motion.
I have not suggested any formulas here please read original post it's not mine. I will say any time resistance training is involved their will be some positive result whether it is a full range of motion or static contraction training.

I am unsure how it can be a leverage system. Leverage means force in one vector. According to your video your arms are free to move so there is no power vector. The only time you have a vector is when you do pull downs. So it does seem like you are overly hyping the product to get air time, so I concur with the guys it would be better if you post it up as a fitness product of a self spotter for dumbbells(though, I am unsure how it would work for power blocks) rather than here.

[boxertim]

dumbelldee has learned a very important lesson on first impressions.....it seems as though he will never get a chance to speak to his product in this forum.

remember...the internet is serious business.

here is my advice....

1)move on and find another forum
2)get a rep as a person who gives good advice
3)put a link to your vid in your sig....you can type a whole paragraph in your sig...sell your product there.
4)keep info about your product in one thread and just link people to it when you want
5)keep doing what you already are....they are all going to be hits on google when you start selling the product.


to the OP....i think that there is not much of a reliable conversion that can be done.....sure both movements are with weight...but the 100m and 200m are both running...and the comparisons between those are guesses at best.


tim

[thecoremachine]

I think the real question was how much weight is he actually pushing considering the formula of leverage created by the lever. a real easy solution to your question would be for you to go to a bait & tackle shop and get a hook scale that accommodates 350 to 400 Lbs. hook the press bar and pull it. you will get a accurate reading of the actual force to move the bar at what ever level you have it set for.