# Why do we want to curl our legs while doing pull-ups **URL:** \ **Category:** Factual Questions\ **Created:** [May 14, 2015, 1:37pm UTC](https://boards.straightdope.com/t/why-do-we-want-to-curl-our-legs-while-doing-pull-ups/720029 "2015-05-14T13:37:25Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![yellowjacketcoder](https://avatars.discourse-cdn.com/v4/letter/y/4bbf92/32.png) [@yellowjacketcoder](https://boards.straightdope.com/u/yellowjacketcoder)\ **Post date:** [May 14, 2015, 1:37pm UTC](https://boards.straightdope.com/t/why-do-we-want-to-curl-our-legs-while-doing-pull-ups/720029/1 "2015-05-14T13:37:25Z")
I was working out the other day, and noticed that when I’m doing pull-ups, I have an unconscious desire to curl my legs while pulling myself up. Two questions really: 1. Why does my body want to do this? 2. Should I keep the legs straight? ---
**Author:** ![TriPolar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/tripolar/32/3008_2.png) [@TriPolar](https://boards.straightdope.com/u/TriPolar)\ **Post date:** [May 14, 2015, 1:46pm UTC](https://boards.straightdope.com/t/why-do-we-want-to-curl-our-legs-while-doing-pull-ups/720029/2 "2015-05-14T13:46:21Z")
I’ve seen something that says a ‘proper’ pull up is done with the legs straight. I believe bending the legs rotates the body forward allowing you to use your pectoral muscles more efficiently in the lift. ---
**Author:** ![Gothic](https://avatars.discourse-cdn.com/v4/letter/g/839c29/32.png) [@Gothic](https://boards.straightdope.com/u/Gothic)\ **Post date:** [May 14, 2015, 1:51pm UTC](https://boards.straightdope.com/t/why-do-we-want-to-curl-our-legs-while-doing-pull-ups/720029/3 "2015-05-14T13:51:14Z")
I always pulled them up to have clearance. ---
**Author:** ![Ethilrist](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ethilrist/32/4604_2.png) [@Ethilrist](https://boards.straightdope.com/u/Ethilrist)\ **Post date:** [May 14, 2015, 1:51pm UTC](https://boards.straightdope.com/t/why-do-we-want-to-curl-our-legs-while-doing-pull-ups/720029/4 "2015-05-14T13:51:42Z")
Momentum. With your legs straight, you’re not using any of the muscles in them to pull yourself up. If you kick your feet up behind you just before you start lifting with your arms, you’ve already got some momentum in your legs so your arms don’t have to work as hard. ---
**Author:** ![The\_wind\_of\_my\_soul](https://avatars.discourse-cdn.com/v4/letter/t/ecc23a/32.png) [@The\_wind\_of\_my\_soul](https://boards.straightdope.com/u/The_wind_of_my_soul)\ **Post date:** [May 14, 2015, 8:23pm UTC](https://boards.straightdope.com/t/why-do-we-want-to-curl-our-legs-while-doing-pull-ups/720029/5 "2015-05-14T20:23:24Z")
When I was younger I used to do pull-ups with my legs straight, no problem. But when I got older, then doing a pull-up with my legs straight would cause my body to swing slightly. If I bend my legs, it keeps my body more steady. Don’t ask me to explain all the science behind it, that’s just what I’ve observed. ---
**Author:** ![Saturn\_Dreams](https://avatars.discourse-cdn.com/v4/letter/s/dc4da7/32.png) [@Saturn\_Dreams](https://boards.straightdope.com/u/Saturn_Dreams)\ **Post date:** [May 15, 2015, 7:42am UTC](https://boards.straightdope.com/t/why-do-we-want-to-curl-our-legs-while-doing-pull-ups/720029/6 "2015-05-15T07:42:48Z")
> [@yellowjacketcoder](#): > > Two questions really: > > 1. Why does my body want to do this? > 2. Should I keep the legs straight? 1. It’s easier for your body core to keep you balanced as you pull yourself up when you’re compact. When your legs are kept straight, they act as “extenders” and makes you more prone to swinging. 2. Doesn’t matter too much if you’re only concentrating on the arms, shoulders and back. If you want to add core and work the glutes and abs at the same time, then bend, not backwards but forward.