Smith Machine Equation

[rambo]

I would think there would not be due to a lot of intrinsic differences between free weights and a smith machine, but is there an equation similar to a rep calculator which would equivalate the amount of weight handled on a smith machine to that of a free press?

Example:

Weight handled on normal bench vs. Weight handled on smith during bench press?

[DBarcelo]

That's pretty much impossible. There are a lot of different types of smith machines. Some have rollers, some just glide on the bar, some have counter weight, some don't have any counter weight, some have 45 lb bars, some have 15 lb bars, etc., etc.

The weight itself reacts the same way as any other free weight, meaning that it follows the same resistance curve, aposed to the resistance curve of bands like the Soloflex uses, or from weight stacks. The main difference is that there is no need to balance the weight quite the same way. Most smith machines do allow some difference between the left and right arm (one arm can be a little higher than the other), but it doesn't allow any front to back movement (you can't move the bar closer to your stomach or closer to your head). There are slanted smith machines, but once again, you can only follow the path of the bars.

I workout alone, so I only use a smith machine at home. I'll see if I can get my hands on a free weight bench and see if I can left the same amount if that would help you, but don't imagine there will be much difference.

[Juggernaut]

For myself, I just count the plates.

[sp9]

I use a smith at home as well. Mostly for safety reasons. I also have a full set of dumbbells. I would think that you could lift more on the smith than with a traditional barbell. This is due to the fixed path, especially after a couple of weeks your body is going to adapt and become very strong along that path. With the barbell you have more stabilizers that come into play. Dumbbells are king in my opinion. If you can dumbbell press 125lb each hand you could barbell press way more than 250 and smith press 350+. Just a guess but you get the idea. I don't see how there would be any calculator since it would vary by person. You could max out on dumbbell, barbell, and smith and then apply that equation to yourself in the future but you would always be recalibrating based on your own improvements or failures over time.

[rambo]

There are just too many musculoskeletal differences in the way the weight is lifted i think. It probably is nearly impossible to tell.

[solidj55]

Dumbbells are king in my opinion.

I couldnt agree more!!!

[FrkyBgStok]

when i use smith machine, i usually don't go for exact weight. I just right down if the bar weighed 45lbs. like regular. I just watch to see if i am going up in weight or not.

[DBarcelo]

I got to a free weight bech this weekend and I was able to lift the exact same as I do on my smith machine. But like I said, smith machines vary a great deal. Mine doesn't use any counter weight or any casters, so I guess that's why I can lift the same on free weight as I can on my smith.