Accommodating Resistance 101

You’ve seen videos online of folks lifting barbells with chains attached to them, or benching against rubber bands fastened to the floor. Bands and chains are training variables that we can play with in certain cases. They both fall under the umbrella of accommodating resistance. What is accommodating resistance and why would someone use it in their training?

Accommodating resistance seems like a fancy thing reserved for athletes at a high level, but its principles are simple and apply to every person and all bodies. In order to understand it, first we must talk about a simple concept with another fancy name, the Force Posture Curve. Let's explain this in simple terms that most people who have spent a few days in the gym can understand. When doing a squat, we can lift more weight or the same weight much easier if we do a half squat vs a full squat, and the same is true of a quarter squat vs a half squat. As we get to the top of these movements it is easier to lift, we are stronger in these positions than we are at the bottom. This, in effect, is the force posture curve, our ability to produce force changes as our posture changes. At the bottom of a lift we are “weaker” than halfway or near the top. 

Knowing this let's consider how bands and chains work on a barbell lift. When set up properly, standing at the top of the lift, the band is stretched as much as it is going to be stretched during your lift, applying the greatest force. The same goes for the chain, most of the chain is off the floor and hanging in space, meaning that extra chain weight is on you at the top of the lift. As we descend the band's stretch is less, and the chains begin to pile on the floor. The force of the bands or the weights of the chain diminishes the lower we get to the bottom of the lift. Once at the bottom, the band is as short as it will get (keep in mind properly set up bands should never be totally slack in this position as this is ineffective and can be dangerous if the band slips off during a lift), the chains are piled onto the floor. This extra load is greatly diminished as we reverse the weight and begin to stand back up. As we ascend, everything happens in reverse. The bands stretch more, applying more resistance, the chains begin to come up off the floor. The weight on your back or in your hands increases as your leverages improve and you can produce more force moving into stronger positions towards the top of the lift. We then finish as we started, with maximum tension or load while also being in the strongest positions we can assume, the lockout out position. These bands or chains forced us to continue to produce more force as we lifted even though we were getting into stronger and stronger positions. They accommodated the resistance to match our force posture curve!

This is great and all but why not just use normal lifts knowing that we will be “stronger” at the top than the bottom. Whether your goal is to build muscle or increase your strength, lifting with normal weights leaves the training effect of portions of these lifts diminished. Let's say you are really weak off your chest on the bench press, but your lockout feels strong. When you bench normally, you are only getting a training effect for the weakest part of the chain, in this case that would be pressing power off the chest. Hooking some bands or chains to the bar would allow you to get this same effect on your weak point, and allow you a stronger signal to other stronger parts of the lift allowing you to get more muscle building and strength out of the same amount of sets and reps in the gym. Outside of the performance benefits, it is simply getting more bang for your buck in terms of time spent in the gym.

If accommodating resistance is so great why doesn’t everyone use it all the time? Well first off there are a couple immediate barriers to entry: equipment, and set up. While they are becoming more and more common, not all gyms have chains or the proper equipment to get up chains on barbell lifts. If your gym doesn’t have them, they aren't exactly the type of thing you can just throw in your gym bag and take with you. They are heavy. Bands, however, are very easy to carry around and most gym goers might already have a pair they use for other exercises. Setting up bands, however, can be tricky. You will require a rack you can hook them to, and as mentioned earlier, it will take some trial and error to find the right set up with your available equipment so that they are tensioned throughout the lift properly. Lastly, it can be hard to make sure you have enough resistance on the bar if you choose to add chains or bands. Chains can be easier to measure, as they have measurable weight, but setting them up properly so they are deloaded at the bottom and 90% unloaded at the top can be difficult. Bands are much harder to measure and unless you are carrying a luggage scale around with you, it can be very easy to have too little or too much band tension on your bar. Remember that accommodation resistance is real weight, so you must consider it when choosing how much weight to put on the bar. Most of the benefit can come from using 20-30% of your 1RM in the chosen lift in accommodating resistance. This means if you squat 200lb, you want between 40-60lb of chain or bands on the bar measured at its highest point, meaning the top position of the lift. In this example a workout that might have been 75% for 5 sets of 5 reps on a squat that may have been 150lb before is now, 100lb of weight with 50lb of bands for 5 sets of 5 reps. Training this way and treating the chains or bands as real weights greatly reduces your chance of injury when using these modalities and maximizes their benefits. As you get more comfortable using accommodating resistance, you can begin to increase the weight on the barbell increasing the training effect of the normal weights while still getting the benefit of the resistance. This workout might turn into 125lb with 50lb of bands or chains for 5 sets of 5 reps in someone who has some time under their belt using these kinds of resistance.

Every situation is different in terms of equipment available. Even a person's height or arm length can play a major role in how much band tension someone experiences when setting up a certain way, or how they need to rig the chains for a proper deload. It can get tricky, but if you have a facility with these available and you are willing to spend some time figuring it out, or ask a seasoned pro or coach for help to make sure you are setting them up safely, adding accommodating resistance into your training from time to time and introduce some variety to keep you interested and begin to training your bodies ability to produce force and stimulate muscle growth along the entire range of motion.