Muscle growth. Behind weight loss, muscle growth is probably the #1 most commonly desired outcome from training. It’s what originally interested me and what keeps gyms everywhere full day in and day out. Considering how many people want muscle growth in one area or another, it seems absurd that most people fight this battle each day and have little results to show. So, let’s break this down and see where most of us go wrong.
Ok, this shouldn’t be too difficult. I mean, some people know how to grow muscle right? We all know at least one person who has made appreciable progress in the gym, which gives us all hope that we can do the same. Yet, very few people actually achieve noticeable muscle growth despite their best efforts. So, what’s going on? Is it genetics? Laziness? The wrong food? A hormone imbalance? Something’s got to give!
Well luckily, its none of those. Sure, those factors can definitely affect your progress. But the truth for most people is, you aren’t STRONG ENOUGH to grow! Let’s explore an example.
Ok, so you want to grow. You might hire a trainer (surely they can make me grow!). Or, you might scour the internet for information on the best ways to train (there’s sure to be an expert online!). No matter which route you go, most of the information you receive will look something like this:
“For maximal muscle growth, use a moderate rep range of 8-12 repetitions per set…”
“Time under tension drives muscle growth. Lift slow to get BIG!”
Sound familiar? The tricky part is, this is not technically wrong. I mean, look at the evidence. Pick up any issue of Men’s Health or snag a copy of your favorite bodybuilding magazine and the articles will be littered with recommendations from the pros that push us to train in the 8-12 rep range. Clearly it works, right??? Yes…for them. What many professionals (athletes and trainers alike) forget is that these repetitions work because of the lifter’s advanced status.
Our muscles grow larger in response to a stress that challenges the ability of the muscle to contract. This is pretty easy to imagine. Every lifter knows the feeling of the weight slowing down as your muscle fights to finish the repetition. It is these slow, maximum effort repetitions, that actually stimulate muscle growth. Every other repetition prior to these was done to reach the opportunity to fight for the reps that actually challenge the muscle. Sounds pretty simple right? This is exactly where the “train until failure” concept comes from. However, training until failure is not the same for beginners and advanced lifters.
To understand why, let’s briefly talk about the two main types of muscle fibers that reside within our muscle. For purpose of discussion, we can think of a muscle as a big collection of ropes (muscle fibers) that work together to move a weight. However, not all of our muscle fibers are active when we lift a weight. Frankly, our muscles want to do as little work as possible and will only activate as many muscle fibers as necessary to accomplish the task. As the weight gets heavier, more muscle fibers are recruited. At low weights, the muscle fibers that do the majority of the work are Fatigue Resistant (FR) muscle fibers. As the weight increases, Fast Fatiguing (FF) muscle fibers are activated to generate more force to move the weight. In comparison, Fast Fatiguing (FF) muscle fibers generate a lot more force (strength), but fatigue much faster than Fatigue Resistant (FR) muscle fibers. Now here is the kicker. Fast Fatiguing (FF) muscle fibers are the fibers that grow in size significantly when trained. Fatigue Resistant (FR) muscle fibers show very little change in size when trained. For a good example, take a look at this comparison of a distance runner and a weightlifter.
We can safely say that both are highly trained athletes that rely on their legs to perform. However, the distance runner mostly activates their Fatigue Resistant (FR) fibers training with very low weight (bodyweight) and the weightlifter activates their Fatigue Resistant (FR) and Fast Fatiguing (FF) fibers training with maximal weight (400+ lbs!). It is clear who has experienced more muscle growth.
So what does this have to do with beginner lifters?
When we first begin to strength train, whether at age 16 or age 65, we have lived the majority of our lives reliant on our Fatigue Resistant (FR) muscle fibers to accomplish most of our tasks. Unless a person has worked in manual labor for a lengthy period of time, most people do not naturally develop their Fast Fatiguing (FF) muscle fibers, and therefore do not show any significant increase in muscle mass. The Fast Fatiguing (FF) muscle fibers of the beginner lifter are underused and are only recruited at the upper end of their strength capacity.
Let’s imagine a beginner lifter with a maximum back squat of 200 lbs. Research on muscle fiber recruitment indicates that we recruit all available muscle fibers at ~85% of our maximum strength capacity. Training close to maximum strength capacity is absolutely necessary for beginners, because their Fast Fatiguing (FF) muscle fibers will be recruited as a last resort and represent a smaller proportion of the total muscle than in advanced lifters. And remember, the Fast Fatiguing (FF) muscle fibers are the fibers that will grow significantly when trained, not the Fatigue Resistant (FR) muscle fibers.
85% of 200lbs = 170lbs
A lifter with a maximum squat of 200lbs could probably lift 170lbs for 5-7 repetitions. This load and rep range gives the beginning lifter the BEST chance for muscle growth! Training at lower loads and higher repetitions, especially up in the 12-15 range, significantly decreases the chances of the Fast Fatiguing (FF) muscle fibers being recruited, and thereby decreases a beginner’s chances for muscle growth. Now, let’s take a quick look at a more advanced lifter.
Let’s assume that same lifter now has a maximum squat of 400lbs. The strength increase that the lifter has experienced has already caused an increase in the lifter’s overall muscle mass. However, the lifter now has options when aiming to stimulate further muscle growth. Remember, Fatigue Resistant (FR) muscle fibers do not change significantly in force production (strength). Therefore, the majority of this new muscle mass is due to an increase in the size of the lifter’s Fast Fatiguing (FF) muscle fibers. The Fatigue Resistant (FR) muscle fibers still represent a similar amount of force production, which means that the lifter can now train their Fast Fatiguing (FF) muscle fibers at significantly lighter loads. This is why you see professional bodybuilders capable of building muscle using 10-20+ repetitions. The imaginary lifter that significantly increased their squat can now train their Fast Fatiguing (FF) muscle fibers anywhere between 200lbs (for ~30 reps, ouch!) and 350lbs (for ~5 reps). This gives the lifter an increased number of ways to train and still grow muscle.
The ability to use higher repetitions to stimulate muscle growth is an earned privilege! In order to have the capacity to grow muscle with 15, 12, or even 10 repetitions in a set, you must be STRONG first. Until then, I highly recommend that beginners stick to learning how to get strong. For most, this will entail focusing on our big, compound lifts and using as much load as you can safely handle for 5-8 repetitions. If you have been struggling with muscle growth and have been pumping out sets of 12-15 with very little noticeable change, then I challenge you to focus your workouts around improving the load you can handle for 5-8 reps on squat, deadlift, bench press, overhead press, hip thrust, and chin-ups. Not only will you likely experience more muscle growth from these workouts, you will become stronger and eventually be able to adopt a bodybuilding style program that will finally be effective. If you have any questions about how to accomplish this, feel free to email me at email@example.com. See below for a good example of how to build strength quickly and simply.
Alternate between these two workouts, focusing on improving your load over the course of 4-6 weeks.
Back Squat – 3 sets, 5 reps
Overhead Press – 3 sets, 6 reps
Deadlift – 3 sets, 5 reps
Hip Thrust – 3 sets, 8 reps
Bench Press – 3 sets, 5 reps
Chin-Ups – 3 sets, as many as possible
If you have not spent time building strength, this workout will seem rather simple. That is because you have not yet learned to lift at the higher end of your strength capacity. As your weights increase, the workouts will become brutally difficult. Good Luck!