Not sure what category this belongs in, but here’s my question: like most of us these days I have been lifting at home for awhile now. Because of this and not being able to afford or have the space for every machine/piece of equipment that a gym has, I use resistance bands for some exercises. The disadvantage of using them is that you have to go up or down in weight in increments of 20 lbs since you loop the bands through and double back using a door anchor. You could directly attach the bands onto the anchors, but from what I’ve read that puts more pressure on the hook side of the bands which increases the chance of them breaking. However, I have done that because I don’t want to have to go up or down 20lbs. My question: Example 1 - if you put a 20 lb resistance band through an anchor it will be 40 lbs of resistance right? If you connect a 40 lb resistance band directly onto the anchor that should also be 40 lbs of resistance as well right? Well, why does the one where you looped it through the anchor and attached both hooks onto one handle feel so much heavier? And I mean, not even close and that’s using the same set of bands. Example 2 - if you connect a 40 lb resistance band directly onto the anchor its 40 lbs of resistance as already stated. If you connect a 30 lb and a 10 lb resistance band directly onto the anchor that should also be 40 lbs right? Well, same type of thing…the 30 & the 10 lb bands feel much heavier as well. It makes it very difficult when I’m trying to combine multiple bands together when I either want to go up or down 5 or 10 lbs instead of 20 lbs when you loop it through the anchor. Example 3 - here’s another scenario, which I thought would solve this problem. 40 lbs (20 lbs looped through an anchor) became too easy, so I put a 20 lb and a 5 lb band through the anchor to get to 50 lbs. This feels even heavier than the examples above and feels nothing like 50 lbs of resistance. Hopefully someone can explain why this is the case. I wish I could afford a nice cable machine, but right now unfortunately I can’t.
Don’t feel dumb.
Elastic materials stretch very differently than
just a basic linear modulus.
For any more clarity you’ll have to ask a real engineer, of which there are many here, and may be more knowledgeable than torch & hammer guy (me).
To add to the confusion, start here:
Thanks. It’s frustrating because since the weights don’t match up correctly unless I always use the same method of attaching the bands. And since putting them through the door anchor is the safest, I guess I’ll just always have to go up in increments of 20. But when you are within the same rep range going up 20 lbs means you’ll get nowhere close to the 8 reps, 12 reps or whatever you are doing at that time. I’ll be doing 8 reps and then eventually be able to do 10 or so reps, so I’ll need to increase 20 lbs but then get way under the 8 reps that I’m shooting for. Oh well…
HA - yes. The joke that is resistance bands. I say “joke” - they work. But the weights on them are useless.
Not only do you have the issues you raised. But the whole idea of a band is 20lb. Per what?
Hooks laws states that an elastic material will stretch a uniform length per force applied. So a 20lb band should be “it takes 20lb to extend this band Xft”. As a band that is 20lb/2ft is twice as tough as a 20lb/4ft.
With regard to rigging / set up - YES - the way you attached the band will effect the amount of force applied to the bar. I’m having a hard time visualising you set up. But from what I can gather you’re talking about the difference of single and double returns. Which is something I’ve used in the past on over head line construction.
In short - bands are good. BUT the secrete is accept that its not as simple to track progress. As there are more variables. For instance - my home gym has a higher bench. And as such when I tie a band off to the floor for benching - it adds more resistance then it does in the gym.
Just treat it like a superset. So you anchor both bands. If you get, say 3 with the heavy band, do another 5-9 with the light one to ‘finish’ the set