Have you ever seen that person in the gym squatting with chains hanging from the bar or maybe benching with bands on either side and thought, “why are they being so extra?”
Although hanging a bunch of chains from the ends of your barbell might seem like a meathead move done for more likes on the 'gram or more looks from fellow gym-goers, it’s actually an evidence-based method that allows for maximal force production throughout the entire range of motion (ROM) of a particular movement (Zatsiorsky, 2021). This method of accommodating resistance is called variable resistance because the total mechanical load, or the weight being lifted, is constantly changing throughout the ROM.
OK, so what does that mean? Let’s take a look at our new friend (we’ll call him Vladimir) who we saw squatting with chains in the gym earlier. Vlad attached one end of the chain to the bar on each side, and let the rest hang down to the floor. As Vlad descends into a deep squat position, more links drop onto the pile resting on the floor; he’s technically lightened the load, making it “easier” as the movement would naturally be getting harder. (Think: is it easier to sit down on the couch or stand up from the couch?)
Now that Vlad is at the bottom of the squat, it’s time to stand back up. As he ascends, the links of the chain are starting to lift off the floor; this makes the load heavier, requiring Vlad’s muscles to consistently generate more force until he’s finally standing upright again. Why is this helpful you might ask? In short, because it’s going to help Vlad get bigger, faster, and stronger. For those of you who’d like to understand the why a little better, I’m going to briefly talk about some pretty cool physiological changes that were occurring within Vlad during his awesome set of squats only moments ago.
You didn't skip science class, right?
For our body to figure out exactly how much force it needs to generate to lift a weight, a multitude of complex processes needs to occur repeatedly in a fraction of a fraction of a second. It all starts with what we call a stimulus, in this case squatting. As soon as we look at the bar and start thinking about picking it up, our body begins preparing itself for the events that are about to unfold.
Our adrenal medullae start releasing epinephrine and norepinephrine. Our cardiac output increases. Our palms start to get sweaty and we might even experience some acute tunnel vision. Then we step under the bar and begin to unrack it, putting immense tension on our musculoskeletal system. Our peripheral nervous system (PNS) transmits information via afferent neurons from this new stimulus to our central nervous system (CNS). Once our CNS receives this new info, it must decide how to respond and then send those instructions to our muscles via efferent neurons as quickly as possible.
Under a typical constant or isotonic load, our body can quickly adapt to the sudden extreme change in its environment by recruiting a relatively set number of motor units that remain more or less unchanged. However, in the case of our buddy Vlad who decided to partake in variable resistance training, the message being sent to his CNS is ever-changing because the stimulus is also ever-changing throughout the ROM of his squat. This causes his body to recruit additional motor units to cope with a now ever-changing stimulus- which means Vlad’s body is now moving more efficiently, leading to increased strength.
To put this into perspective, think about the last time you moved to a new house and had to get that huge couch from the living room to the moving truck. It’s a lot easier to move the couch with the help of a few friends than it is all by yourself.
You and your friends are equivalent to those motor units I was talking about above. Same idea.
Implement new knowledge
So the next time you hit that plateau at the gym, or you want to try something a little different (and harder), try adding bands or chains to an exercise or two. You might just find that if you stick with it for a bit, you’ll push right on through that plateau and hit a new PR. And of course, don’t be afraid to reach out to one of our trainers if you’re not quite sure how to implement this strategy into your workout programming, or even if you just have questions and want to chat about this awesome training concept.