The physics of pull-ups

Some people are naturally better than others at pulling off the elusive pull-up, writes Kyle Hill at Scientifica American. For them, it's all about mass-to-arm-length ratio — ideally, you want a low mass and short arms to minimize the amount of energy it takes to pull your body upwards. But Hill insists that the less genetically fortunate can learn to do pull-ups, too. It's just something that takes dedicated training.


  1. That roughly applied to my high school friend Bill’s family: short, broad shouldered, but not too heavy.  Interestingly, I was taller, much longer arms, and that somehow gave me a very large advantage on the “opposite” exercise, the bench press.  And also curls.  Bill developed much more impressive-looking muscles than I did, but I always lifted far more weight.

    We were about even when it came to pull-ups: but that’s not where I’m going with this.  His father had grown up an Arkie picking fruit in the valley.  Well into middle age he could do one-arm pull-ups.

  2. Another note about pull-ups: for a while, with the idea of maximizing my workout, I was incorporating “crunches” into my pull-ups.  At first I felt good about getting some extra ab work in with the lats, but I quickly realized that depending on the timing, the crunch became a cheat:  If you began pulling your legs up as you were lifting your body, you were basically creating upwards momentum for your center of gravity with your stomach, taking pressure off of your arms.  That said, if pull-ups are hard/impossible for you, that “cheat” might be a good way to get into them.

    1. Hold your legs extended and parallel to the floor while doing your pull-ups. Or better yet, in pike position. No, I have no personal experience of this.

  3. Some people are naturally better than others at pulling off the elusive pull-up.

    Shoot, even my toddlers can pull off a pull-up. But we’re almost done with potty training so we shouldn’t need them much longer anyway.

    1. Yeah, that’s exactly what I thought of when I read this in the RSS feed.  I was kinda confused for a few seconds.  
      Kids.  They ruin our thought patterns.  

  4. I was hoping for more details about the nature of the “dedicated training” but was disappointed.

    I can usually manage exactly one good pull-up, and I am at something of a loss as to how to work my way up to more than one.

    1. It’s hard to make any incremental progress when your smallest possible improvement is to double your prior performance. My first instinct would be to go to assisted pull-ups (which use an elastic band or a counterweight to support you from below) so you can do more reps.

    2. The most important/difficult part with any exercise is having correct form.

      Once you have that, building up is easy and the same approaches apply to most exercises. 

      For informational purposes only; use at your own risk.

      Vary intensity, repetitions, form. 
      Try out different hand width and positioning 
      Assistance: pull-up machines, human spotting, bands
      Do negatives: get assistance on the up motion and fight it on the way down
      Work the muscles with other exercises. The pullup is a good strength predictor as it uses many different muscle groups synergistically, from your upper arms to your back and core.

      Slight doms is a good sign. Keep track of what worked and what didn’t, and wait for doms to pass before working the same muscle again.

    3. Do the negative portion of the pull-up, the down motion, until you can lift yourself a few times (may take a few weeks). Try to lower yourself as slowly as you can.
      This should help you progress a bit faster than assisted pull-ups as you will have the full load of your body weight on your muscles. Fewer reps at higher resistance yield greater strength gains than more reps with less resistance (endurance).

  5. I had to read through the whole thing twice to figure out why someone needed training and strength to deal with toddler diapers. Then the light bulb went on…

  6. It is physically impossible for a human being to do a pull-up. EVER.

    Funny how it’s the most obvious urban legends that we’re the most likely to fall for, or even swear that we witnessed them ourselves. Next you’ll be telling me people can climb ropes, or make a free throw with the whole gym class watching!

    1. Hey now, I liked climbing the rope.  None of the other girls could do it, and only a few of the boys.

  7. I’ve heard that instead of trying to pull yourself up, you concentrate on pulling your elbows down.  In my experience, I _think_ it help a little… perhaps it helps fire the lats more or something.

    1. I concentrate on touching the bar to my chest, and it seems to go more easily.  I generally do about ten, but it took me a while to work up to that.

  8. No wonder I have had problems with this. I am six feet tall and light of build. But my armspan is 6’4″. Mostly went for distance running until I took an arrow to the knee broke my ankle

  9. Odd. I have long arms and a high body mass for my height, yet I’ve always been able to crank out more pull ups than the average person. (x20-30 @ 200 lbs 5″11 w/ 76″ reach)

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