# How do I convert from band resisted pullups to weight resisted pullups?

I have a doubled over red band which I anchored with a strap to the ground. I calculated that it provides about 30 pounds of resistance at the top of the movement.

However, it resists less at the bottom of the movement than at the top, unlike a weight which provides even resistance throughout. How do I convert band resisted pullups to weighted pullups so I can take that number and plug it into a "One Rep Max" calculator?

The reason I'm asking is that I saw a Youtube video with a guy who trained to lift his gf on a pullup, so I wanted to try that. Currently I'm doing 7 reps of bicycle + backpack + red band. I weigh 220 fully dressed; so that should work out to: 220 + 40 + 10 + 30 = 300 pounds for 7 reps, but the problem is the red band changes over the movement so I don't know how to figure it into the calculation.

• Why don't you just do a weight resisted pullup to benchmark? There's not a 1-to-1 conversion here, as this differs from person to person. – Alec Oct 7 at 8:47
• @Alec I am doing weighted pullups of +50 pounds (bicycle + backpack), but with the gym being closed, I am biking to the pullup bars and its not like I can keep adding plate weights to my bike bags because 1. I don't have a set of plate weights 2. Even if I did that would be a lot to cart around up and down the bike path. - I do have bands so I started tying the bike to the ground with a band and lifting the whole contraption. – SurpriseDog Oct 7 at 14:14
• Well for one thing, the calculators are estimations, not canonical predictors. Secondly, I don't know how well the 1RM calculators work for bodyweight-style exercises. Are you sure the formulas being used are meant for your purpose? – Alec Oct 7 at 16:24
• @Alec weight is weight whether a body or a stack of 45 pound plates is providing it. The calculator I'm using is supposed to be for "upper body strength" so it should be close enough. I will try again once the calculator says I can do 330 for reps and see how accurate it is. I just posted the question because I wanted to know how close I am using a combination of bike + backpack + bands. – SurpriseDog Oct 7 at 16:35
• "weight is weight whether a body or a stack[...]" That logic doesn't hold. If the calculators you use are calibrated based on data from powerlifts for example, there is no expectation that it will be useful for other types of lifts. – Alec Oct 7 at 19:48