A few weeks before the big "Shut Down," or "Quarantine," or "Jailing,"...whatever you chose to call it, we had a young lady drop in for a workout. She was from the west coast, somewhere in California, and decided to make MOEfit her temporary soul crushing spot while on vacation. As is customary, we discussed her fitness history and current abilities so that I could gauge how to suggest she approach that days WOD....scaling/modifying etc. She looked to be in very good shape, and had been a member and regular attendee at a Crossfit gym back in her home state for a couple years. Cool. Then it came time to get into the WOD, which included strict pull-ups. I'm a big fan of strict pull ups vs. kipping. In real world situations kipping is useless. We allow kipping in these situations
but it's considered a scaled move. Anyway, in the few minutes before the "3..2..1..GOOO!," when everyone is organizing their equipment for the workout, she grabbed a resistance band and through it over the pull up bar at her station and banged out a couple band assisted pull ups.
Will standing on a resistance band and using it to literally sling shot you over the bar allow you to do more pull ups in a metcon? Of course it will. You can always do more of anything when you cheat!! That last statement may trigger a few of you but think it through before you decide to label me a pull up snob.
If you can't perform a strict pull up, meaning you start from a dead hang, use only your arms to lift your body straight up so that your chin is higher than the bar, and then lower yourself back down to a dead hang, then strengthen the muscles you need to strengthen, don't replace them with machinery. That's exactly what you're doing when you use a band, you are replacing your own muscles with a machine. How is that helping you at all? It isn't.
When you perform a pull up, muscles in your back...mainly your lats, rhomboids, delts, and to some extent your bi-ceps (more so in a reverse grip or chin up)...work together to get you over the bar. If you can't lift yourself through the full range of motion in a pull up it simply means these muscles aren't yet strong enough. If you hang a resistance band from the bar to stand in while you do the pull ups, you aren't doing anything to strengthen these muscles. In order to strengthen the muscles you need to stress them beyond what they are currently capable of, and if you "help them along" with the bands, you are letting them do what they can already do and then using a machine to finish the job. No strength has been gained. Sure, you got the reps in, but you cheated. More importantly, you cheated yourself out of an opportunity to build strength as opposed to putting a nice number on the whiteboard.
What to do instead.
There are 2 obvious ways to get your body into pull up mode. You can either build your strength to lift what you weigh, or weigh less. Usually a little of both is the answer.
Let's look at the second option first. If you are overweight or obese, you are going to need to build your muscle strength considerably to be able to lift yourself over the bar. In fact, it may not be possible. First and foremost, it will take a level of discipline that you probably don't have..,otherwise you wouldn't be in the shape you're in to begin with. That leaves the obvious answer...lose the weight! This isn't a weight loss post, so no point in diving into how to do that, but if you are dealing with a weight issue, then you probably already know what you need to do with both lifestyle and nutrition. So go do that.
Now for the other approach...make your pull up muscles stronger. I believe I've adequately shown above why band assisted pull ups do you no good at all. The way to approach this is to simply do modified pull ups that still work the muscles you need to work in the same way they do when you are doing full range of motion pull ups.
The Jumping Pull Up. In a jumping pull up you set up a box under the pull up bar at a height such that when you stand on it your head is roughly 6 inches under the bar. Put your hands on the pull up bar and hang from it so that your legs bend but your feet stay where they were when you were standing. When you perform a jumping pull up, it's important to remember to use your legs only to help, not primarily. Using your ARMS, pull your chin up higher then the bar, and then lower yourself down. Your legs are only used to help. Over time your legs will be helping you less and less until eventually you can do the move from a dead hang.
Negative Pull Up. This is often the next step after a jumping pull up and builds off the strength you've developed doing Jumping Pull Ups. In a Negative Pull Up, use your legs to jump up so that your chin is higher than the bar, but now you are going to hang from the bar with your feet not on the box. Lower yourself down to a full hang at a deliberately slow speed. Half the speed of a normal pull up or even slower. By doing this, you are using all your pull up muscles exactly as you would in a real pull up and in the same direction as well. That sounds counter-intuitive, but it isn't. I know you are lowering yourself, not pulling, but the same muscles you use to pull up are still under tension on the way down. If it were the opposite muscles you would be doing a shoulder press.
The hard way is the most productive way.
Well, usually. By and large, if the way you go about strength training feels in the back of your head like you're cheating, you probably are. And I don't mean cheating like cheating on your S.A.T's. I mean simply that you are cheating yourself out of the benefits you are shooting for. Why would you pay for that gym membership, get up early, do all that meal planning, buy all those workout cloths, and then give a piece of rubber the workout you meant to give yourself???
One last thing....there are plenty of other auxiliary exercises you can also perform to build your pull ups, the lat pull down machine is a prime example. This machine very closely mimics the pull ups and allows you to load weight to match your current ability, and increase over time.