# Thread: Resistance Bands to Dumbbells

1. ## Resistance Bands to Dumbbells

How do resistance bands transfer to dumbbells. What I mean by that, is there a weight difference between bands and dumbbells. For example, if I can bicep curl 85 lb resistance bands can I do the same with 85 lb dumbells? Or how does that work?

I do a lot of resistance band training from home but I recently joined a gym. I want to have a general idea of the amount of weight I can handle at the gym.

Any info and help would be awesome!

Thanks!

2. I would say you cant do 85lb dbs, (i could be wrong though) but your resistance bands should be 85lbs at the top of your movement but at midpoint maybe only 35-50lbs.

you need to remember a dumbell is a solid weight, if you have a 30lb dumbell its gonna be 30lbs on the bottom of the movement and the top. A resistance band isnt like this, at the bottom it can be 15-20lbs and at top be 85lbs.

If I was you i would start out w/ 20lbs and see how easy or hard those are, then work up w/ 5lb incriments (example 20lbs, 25lbs, 30lbs, 35lbs ,etc.)

3. Originally Posted by Quackers
How do resistance bands transfer to dumbbells. What I mean by that, is there a weight difference between bands and dumbbells. For example, if I can bicep curl 85 lb resistance bands can I do the same with 85 lb dumbells? Or how does that work?

I do a lot of resistance band training from home but I recently joined a gym. I want to have a general idea of the amount of weight I can handle at the gym.
You're just going to have to try different dumbbells for various movements.

A resistance band's resistance varies depending upon how much it's stretched. Therefore, the band's initial stretch will determine the starting resistance. Also, as you stretch the band further during the movement, the resistance increases. Furthermore, the direction of resistance is in the direction in which the band is stretched - this seems obvious, but it's important.

The resistance provided by a dumbbell is determined by the mass of the dumbbell and the gravitational field in which it moves. Gravity on the Earth's surface can be considered to be pretty much constant, so the resistance provided by a dumbbell is constant with respect to the Earth's center (of mass). The direction of resistance provided by a dumbbell is always down. This means that you may have to orient yourself differently with dumbbells than with what you're accustomed to when using resistance bands.

For something like a dumbbell press, the dumbbell will provide a constant resistance all the way through the range of motion, whereas a resistance band press will provide increasing resistance the further you stretch the band. Other types of movements, such as dumbbell curls, are more complicated to analyze since the directional component of the vector provided by a resistance band changes throughout the movement. Also, the mechanical advantage provided by your arm varies throughout the movement.

Below is a chart showing the resistance at various amounts of stretch (deflection) for Lifeline USA resistance cables. If you have these exact cables, then you might be able to estimate the starting and ending resistance. Otherwise, you'll need to go to the gym and experiment.

4. Hey Guys,

Thank you both for the good posts. I'll just have to experiment next time I am at the gym.

I do have these exact cables with my mine being the Green R8 80 lb band.

Thanks!

5. Originally Posted by Quackers
I do have these exact cables with my mine being the Green R8 80 lb band.
In that case, see http://www.lifelineusa.com/FAQ to see how they measure resistance.

According to that page, for that 80lb cable, you'll get 80lbs of resistance when place an anchor at the center of the cable and stretch both handles to three times the unstretched length. The combined tension on both handles is 80lbs, so each handle individually should provide a force of 40lbs. Note that this is roughly what the chart I posted earlier shows. Three times an unstretched length of 2.5 feet is 7.5 feet, giving a deflection of 5 feet. That chart shows a resistance of around 78lbs at that mark.

6. Originally Posted by KBKB
You're just going to have to try different dumbbells for various movements.

A resistance band's resistance varies depending upon how much it's stretched. Therefore, the band's initial stretch will determine the starting resistance. Also, as you stretch the band further during the movement, the resistance increases. Furthermore, the direction of resistance is in the direction in which the band is stretched - this seems obvious, but it's important.

The resistance provided by a dumbbell is determined by the mass of the dumbbell and the gravitational field in which it moves. Gravity on the Earth's surface can be considered to be pretty much constant, so the resistance provided by a dumbbell is constant with respect to the Earth's center (of mass). The direction of resistance provided by a dumbbell is always down. This means that you may have to orient yourself differently with dumbbells than with what you're accustomed to when using resistance bands.

For something like a dumbbell press, the dumbbell will provide a constant resistance all the way through the range of motion, whereas a resistance band press will provide increasing resistance the further you stretch the band. Other types of movements, such as dumbbell curls, are more complicated to analyze since the directional component of the vector provided by a resistance band changes throughout the movement. Also, the mechanical advantage provided by your arm varies throughout the movement.
Indeed. If we look at dumbbell preacher curls, once you pass roughly 90 degrees to the plane of the floor, the biceps are not significantly involved in supporting the weight. moreover, from the beginning of the movement until 90 degrees, the involvement of the biceps is decreasing steadily anyway. don't get me wrong, I do dumbbell preachers pretty often, but this is just how it is. resistance band preacher curls are the opposite: up to and past 90 degrees the "weight" continues to *increase*. Cable machines are roughly constant throughout. So for certain movements, paradigmatically preacher curls, there is basically a continuum from dumbbell through cable to bands, where you go from maximal resistance at the *start* of the movement, through roughly constant, to maximal resistance at the *peak* of the movement...

7. Are all bands the same resistance regardless of the company who makes them?

8. Originally Posted by glap1950
Are all bands the same resistance regardless of the company who makes them?
No. Companies who make resistance bands have different ways of determining the resistance of their bands. You cannot count on a band of a particular resistance to be the same between different manufacturers.

You should also know that the bands resistance changes depending upon how much it is stretched. So, e.g., a 10lb band will only offer 10 pounds of resistance at a particular of stretch (deflection). When not yet stretched to that point, it will be less, and when stretched beyond the "10 lb" point, it will be greater.

This is covered in more detail in earlier posts to this thread.

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