The Best Rep Range For Muscle Growth: Clearing Up The Confusion

The Best Rep Range For Muscle Growth: Shedding Light On A Controversial Subject

How Many Reps Heading

As the heading of this article suggests, this is one very controversial subject I am about to jump into. As one fitness author once stated. If you really want to start one big bloody fight, walk into a room filled with personal trainers, strength coaches and physiological therapists, ask which rep range is the best, and then take cover!

Yes, it really is that controversial and experts in the field are very divided and just as passionate about their own personal convictions. Just to clear things up, if you are a bit in the dark about what exactly are being discussed...

The amount of repetitions (reps) performed per set of exercise to achieve the best possible result, in most cases muscle growth and strength, is the topic of conversation. (Obviously this includes the best rep range to get in shape in general and get a overall toned body.)

You can blame the whole controversy and different approaches on the 2 type of muscle fibres in your body.

Fast-Twitch And Slow-Twitch Muscle Fibres

Muscle Fibres

Fast-Twitch And Slow-Twitch Muscle Fibres are the two types of muscles found in your body. They differ quite significantly in the way they function and respond. 

Fast-twitch muscles are more abundant in the body, and also bigger in size than their slow-twitch cousins. They are also much stronger, and is used for big explosive movements, especially with heavier weights. Professional weight-lifting and sprinting are examples of where the use of fast-twitch fibres come into play. Unlike slow-twitch fibres they respond best to lower repetitions with heavier weights (typically 4-6 reps).

Not as abundant as fast-twitch fibres,  slow-twitch fibres are also the weaker of the two. However, slow-twitch fibres take much longer to fatigue, and are ideal for endurance activities like long distance running and cycling. They also respond best to higher repetitions with lighter weights (typically 16-20 reps).

Rep Ranges And The Different Schools Of Thought

With this in mind, it should come as no surprise that strength coaches and advocates of developing fast-twitch muscle fibres, strongly defend the "heavy weight, low reps" approach. A long rest between sets, normally 3-5 minutes, is followed to allow the muscles time to recuperate before the next heavy set.

Bodybuilders however, traditionally followed a "higher repetition" approach, normally between the 8-12 rep range. In general, they also follow an approach of "training to failure" with relatively heavy weights. (Training to failure means performing a set until you are unable to perform another repetition.)  Rest periods between sets are between 90 seconds and 2 minutes in general.

If you compare professional weightlifters and bodybuilders, it is very clear that bodybuilders are a lot bigger, with more defined muscles and less body fat. Yet, weightlifters are much stronger. More on that later.

To throw a third spanner in the works, there is a relatively new school of thought, advocating sets with long repetitions (16-20 reps) with very little rest in between (40 seconds or less). The argument is that the entire muscle is exercised (both fast-twitch and-slow-twitch fibres) through a process called progressive overload, resulting in muscle growth.

Making Sense Out Of The Chaos


Yes, it is very confusing to say the least. But what if I tell you that all these approaches mentioned in the previous section all have legitimacy? The only way to make sense of it all, is to break it down point by point and look at the facts:

1. Always Consider Your Ultimate Goal

Always take into consideration what the goal of the whole website is. To help men and women of all ages get and stay in shape. It may mean different things for different people. However, in general this means building some muscle, burning fat and in the process create a well-toned and healthy body. Does this mean that all the routines and principles followed by the extreme disciplines of weight training like endurance training (long repetitions) and weightlifting (short repetitions) should be completely avoided and ignored? Not at all! 

2. Progressive Overload: What It is And Why It Is So Important

This is probably the single most important principle to remember no matter what your goals are when it comes to weight training. If you want to see and keep on seeing changes in your body, you need constant Progressive Overload. But what is it and why is so important?       

In short, Progressive Overload is the continuous pressure being put on the body, forcing it to change. It can best be explained by looking at the beginner weight trainer. Whenever you start training with weights for the first time, you see your body changing very quickly, for the first 3 to 6 months anyway. Your body has never experienced weight training before, so it needs to adapt quickly to these new forces being put on it.

As we all know, the body is extremely good at adapting though. In general this a very good thing, but not so much when you want your body to keep changing. You experience this first hand when, after 3-6 months of weight training, the changes to your body starts slowing down and even come to a complete standstill. (In weightlifting terms it is commonly referred to as hitting a plateau.)  The only way for your body to keep changing, is to force it by applying more stress on it. This can be done in a variety of ways.  Increasing the weights you use, adding more reps to your sets, as well as shortening the rest periods between your sets are all methods used to stimulate progressive overload.   

Very few people dispute this principle. It is the way to reach this point where the body get stimulated enough to change, that brings me to the 3rd point.

3. Different Ideologies, Same Claim

I f you look at the advocates of short and heavy weight training, the goal is to use heavy weights which allows you you to do no more than 3-5 reps before reaching failure, using fairly quick explosive movements. This stimulates the fast-twitch fibers into growth. When a weight can be successfully lifted for 5 or more reps, the weight is increased to stimulate more growth. The principle of progressive overload is applied.

Advocates of the 8-12 rep range, aims to do the same. Slower and more controlled movements are used however, to exhaust the slow-twitch fibres and allow the fast-twitch fibres to come into play through the use of more repetitions. Again, the principle of progressive overload is applied.

Again, advocates of the 16-20 rep range also aims to do the same. Using very slow controlled movements with plenty of repetitions puts the focus primarily on slow-twitch fibres. The goal and theory is that by completely exhausting these fibres, with very little rest between sets do you get to fully stimulate the fast-twitch fibres once the former is completely fatigued. And yet again, the principle of progressive overload is applied.

Does this not leave us with the same unanswered question: Which rep range is best? Not really. We now have some clear facts and can see some familiar patterns emerging that will help determining the best option...

A Logical Conclusion

You will probably not be surprised to know that there are plenty of research supporting all 3 ideologies, as all of them are effective to some extend.

One ideology seems to stand out though. The 8-12 rep range appears to be the sweet spot. No, it is not because it is right in the middle between the other 2 more extreme viewpoints. Research backs this up, and leans heavily in favor of using this rep range with moderate weights for maximum results.

Remember the importance of stimulating both fast-and-slow-twitch fibres? Studies have shown the 8-12 rep range to put just enough stress on the slow-twitch muscles fibres to exhaust them fairly quickly before activating and putting the stress on the fast-twitch fibres. A fairly short rest period (approximately 40-50 seconds maximum) is also recommended to enhance the effect of progressive overload and stimulate the maximum amount of muscle fibre.

There are 2 other big advantages of using this rep range. First, using a high (16-20) rep range often cause your supporting muscles, joints and ligaments to tire before the bigger muscles you are targeting becomes fatigued. This causes you to stop prematurely or use too light a weight to finish your set, making it completely ineffective.

The second advantage may be even more important. Using a very heavy weight places your tendons and joints under a lot of pressure, making you more susceptible to injury. The same apples to using a high rep range, with the accumulation of reps building up unnecessary stress and tension on your joints and tendons. 

A Final Thought

So, we have determined the 8-12 rep range to be the most effective range for the best results (with which many experts will disagree no doubt). Does this mean the other schools of thought can be completely be disregarded? Not at all...

Remember your body's amazing ability to adapt? Well, even wit this "ideal" 8-12 rep range routine and even continuously adjusting your weights to keep you muscles stimulated through progressive overload, you will still find yourself at a sticking point or plateau at some point, where you just can't seem to make any progress.

This is the perfect time to set aside a week for some heavy weight, low repetition lifting. Making a sudden change like this has shown to "catch your muscles off-guard"  and stimulate fresh growth. You may even want to add a second or third week of heavy training before returning to your usual routine. As I mentioned in other articles, don't be afraid to experiment.

A lot more can be said and debated about the topic of the best rep range, but I trust you now have more clarity on the issue that will help guide you through your workouts. 

As always, feel free to leave me a comment or suggestion, and remember to join my  mailing list  to get informed whenever a new article is released, as well as helpful hints & tips and news on new developments.

Until next time, take care and let me know if there a specific new topic you would like me to discuss.



About the Author

Wessel Wessels owns his online web and social media design company. However, with nearly 30 years experience in the fitness industry, working out and staying in shape have always been a big passion. After a life-altering close shave with cancer, this experience helped him get back into shape and regain his health. He is now dedicated to helping men and women of all ages to get fit and in shape, and promote a healthy lifestyle.

Leave a Reply 0 comments

Leave a Reply: