In my previous post on the basics of hypertrophy training, I gave a high-level overview of progressive overload. To summarize, progressive overload is simply increasing the number of reps or the weight you lift on a week-to-week basis. I argued that this is the only thing you need to do to guarantee that you grow bigger, stronger muscles. How is that possible? It can’t be that simple, right? Isn’t there a catch?
Yes, it is that simple, and yes, there is a catch.
We can think about it as the actual cause of hypertrophy versus the proximal cause. Progressive overload is the proximal cause of hypertrophy. It is the thing that causes the thing that causes muscle growth. The actual cause of hypertrophy is the thing that causes muscle growth and it can be simply called tension.
Muscular tension
Sometimes people use the term “mechanical tension” or “time under tension” and while there are some differences between those and other terms, they all end up being tied to muscular tension in one way or another. At the end of the day, we are not talking about an electrical stimulus that causes your muscles to grow, for example, so shocking your muscles into growing is not possible. What causes the body to engage in hypertrophy is the stimulus of physical muscular tension.
Muscles have only one function: to contract. At a basic level, they are attached at 2 points, point A and point B, and when the muscle contracts, it brings points A and B closer together. That’s it, that’s all muscles do. Muscular tension is experienced when the muscles contract. The heavier the load, the more times you have to lift the load, the number of sets you do, how slowly you lower the weight while tensing your muscles, all lead to greater muscular tension.
This is the stimulus that actually causes your body to grow its muscles. Everything you do when you lift weights leads directly to improving and maximizing this stimulus.
The closer you get to muscular failure as you lift, the greater the stimulus. Lifting a weight 10 times and having it be as easy on rep 10 as it did on rep 1 will not cause hypertrophy. You have to be barely able to lift that weight on the last rep for it that rep, or possibly even that whole set, to be maximally hypertrophic. I will go into rep numbers and failure in more detail in another post, so let’s just say for now is that it’s important to go close to failure. Not necessarily to failure every time, but close to failure.
Here’s the thing; people are really good at lying to themselves about how close to failure they are.
The “trick” of progressive overload
Very few people are wired in such a way that we can force ourselves to do extremely uncomfortable or painful things. The human body has simply not evolved to put itself into uncomfortable positions. We often lie to ourselves when we work out and say “man, that was hard” when the truth is that if you had more motivation, or a coach yelling at you, or a crowd watching you, you may have been able to do way more reps or lift a way heavier weight than you did. While any amount working out in and of itself is good, certainly better than not working out at all, a workout that was minimally challenging is not going to be nearly as efficient at getting you closer to your goals as a workout that was maximally challenging.
This is where progressive overload comes in. Let’s say that if a coach tested you to push yourself to the limits right here, right now, you’d be able to lift 20lbs 10 times in a row. That’s your max right now - 20lbs for 10 reps. You would fail the 11th rep if you tried it. Progressive overload “tricks” you into doing 10 reps and then going for the 11th rep next week or trying to do 21lbs for 10 reps next week instead of 20lbs.
If you seriously underestimated yourself (or lied to yourself) about how much you can lift, you may have started your workout program doing 10lbs for 10 reps instead of 20lbs. That’s not a big deal with progressive overload in place. Next week yo do 11lbs, then 12, then 13, until you get to 20lbs 10 weeks later. You’ve been able to increase your weight ever week for 10 weeks because your actual max was 20lbs for 10 reps the whole time. Now that you’re at your max, you are pushing to failure and you’ve been pushing close to failure for at least a couple of weeks. Next week the plan is to try 21lbs. Maybe you hit it, maybe you don’t, but you are guaranteed to have stimulated hypertrophy.
Let’s look at it from the perspective of increasing reps, which is my preferred progressive overload method. If your actual max is 100lbs for 20 reps and you start lifting week 1 with 100lbs for only 10, you will reach the 20 rep max at 100lbs in 10 weeks. Starting at week 8 when you’re lifting 100lbs for 18 reps (or within 2 reps of failure), you’re definitely stimulating hypertrophy. Same thing with week 9 where you are one rep shy of failure and again on week 10 when you are hitting what used to be your previous limit of 20 reps. Now you’ve had 3 weeks straight where you pushed yourself close to failure or to failure and all those weeks leading up where you’ve been perfecting your ability to do a lower number of reps. It’s totally possible that you’ve already stimulated enough hypertrophy to be able to hit 21 reps next week.
You are essentially bypassing your own mental limitations and forcing yourself to push to the limit by employing progressive overload. You’re tricking your own brain so that you don’ lie to yourself and avoid doing the hard work required to achieve results. As your muscles get bigger and stronger, they require a greater tension to continue to grow. Progressive overload will necessitate that you push yourself to new limits and provide that stimulus. If you write down how much you lift every week and try to increase those numbers over time, you are guaranteed to get results.
Chase the cause, not the effect
Being able to lift heavier weights for the same number or reps or more reps for the same weight is the effect of muscle growth, not the cause. The cause of hypertrophy is the tension you’ve been putting on your muscles, signaling your body to build more. The fact that you can lift more now is proof that your muscles have grown.
The reason progressive overload works is that you are necessarily putting increasingly greater tension on the target muscles week-to-week. There’s no way to cheat the system, you simply have to try to push yourself past your limits and that push will be what gets you results. Your numbers will increase because your muscles have grown.
It’s important to keep in mind that the the goal of weightlifting for hypertrophy is to stimulate growth, not to hit new personal records. Something that often happens to lifters that intend to follow progressive overload practices for hypertrophy purposes is that they focus too much on getting to that next number, whether it’s reps or weight. They end up sacrificing their form on a lift, potentially risking injury, just to get the weight up. Or maybe they take longer breaks between sets to recover more and pump out another rep at the end of a set that they overwise would not have done.
You should stick to the same high quality form with full range of motion on every rep of every set and only count the reps that you fully complete. That means not counting partial reps or reps where you had to cheat on your form to complete the rep. The only way you know that you’ve actually grown muscle is if you only count the exact same reps every time.
It’s OK if you don’t hit a new number this week, or even if you don’t hit it next week. You should focus on maximally stimulating your muscles through tension on every rep you do, taking each set close to failure. As long as you eat enough protein, have a caloric balance that fuels your body to build muscle, and allow your body to recover through sleep and rest days, you will hit that number within a couple of weeks.
To put it simply; chase the cause, not the effect of hypertrophy. Progressive overload may help you get the stimulus, but the numbers only go up if you’ve stimulated the muscle to grow.
P.S. Building muscle takes a long time and you don’t always notice your progress visually. Outside of weighing yourself, seeing your rep and weight numbers increase over time is the best way to know that what you’re doing is working and you’re building muscle.