Should You Do High Reps Or Low Reps?

If there’s one question I get more than any other on the gym floor, it’s this:

“How many reps should I do?”

Whether your goal is to lose fat, or to build lean muscle, the fact is most gym users are a little lost when it comes to how many reps they should be doing per set to maximize their potential results.

If you’ve been performing 8-12 rep believing it’s the best way to build more muscle in the gym, as per the advice found in muscle building magazines, you might want to think again.

Today we’ll look at some startling research which will change the way a lot of people train forever.

Given that my goal is to stay lean and well built throughout the year, people often look shocked to find out that I do a fair bit of high rep training, as do my clients.

Even the biggest guys I train.

That’s because high rep training is often unappealing to the male ego, or labelled “for toning up”.

But check this:

High rep training has been scientifically proven to build just as much lean muscle as low reps.

And if you’re purely sticking to the so-called “golden” 8-12 rep range, you are missing out on potential results.

should you do high reps or low reps
Dwayne Johnson blasts through another 50 rep set of shrugs in the gym.

The Big Rep Mistake

Walk into any gym around the world, and you’ll see guys making this simple mistake:

Hulking the biggest pair of dumbbells around, with no care for technique, pushing out an unconvincing 8 reps.

Their ego will not let them train with a lighter weight.

If there’s one thing I’ve learned in all my years training, it’s that ego is the enemy of success.

(Perhaps that’s more true now than ever before, in this age of social media “experts” who are constantly patting themselves on the back for their own awesomeness!)

Some guys would rather do eight s**tty reps with poor form, than 8 good ones if it means using a lighter load. At some point, they stopped training their muscles and started training their ego.

In these cases, obviously, using a lighter weight for more reps would be a superior way to build muscle because the muscle would actually be doing the work.

But it also runs a little deeper…

high reps vs low reps

You Weren’t Taught This

There are three rep ranges we should be training in, each comes with it’s own primary goal.

These are things we are taught on personal training courses, and things we pick up from years of experience. They are:

  • 1-5 reps for strength
  • 8-12 reps for muscle growth
  • 15-25 reps for muscular endurance

So given that the majority of us are trying to get a little bigger, it makes sense that most guys see this quick analogy and stick mainly to the 8-12 zone, right?

Sure, they’ll sometimes drop as low as 1-5 reps, or as high as 10, as this allows us to feel the most impressive with regards to the weights we’re throwing around, but that’s as adventurous as it gets.

But guess what – the analogy above is incorrect. It is missing out some crucial information. It should read like this:

  • 1-5 reps for strength and neuromuscular connection (mind/muscle connection)
  • 8-12 reps for muscle growth and strength
  • 15-25 reps for muscular endurance and muscle growth
Sylvester Stallone Rambo workout
Sly is a firm believer in high rep training.

High Reps Vs Low Reps

Several studies have found high rep training to be just as productive as low rep training (and in some cases even more so) for building lean muscle.

But it’s all still relatively new information.

The first study to do this was published as recently as 2010.

Researchers from Canada had a group of subjects perform four sets of leg extensions using their 4 rep max while another group performed the same exercise with their 25 rep max. (1)

The group who did the high reps increased muscle protein synthesis (muscle building) by an astonishing 60%!

should you do low reps or high reps

This study opened many people’s eyes to the potential muscle building benefits of training in a high rep range, but one drawback of the study is that it used a 4 rep max. Very few people train for this low number of reps, and given that it’s in the “strength” zone, it’s not a 100% accurate comparison of high reps vs low reps when it comes to lean muscle growth.

For that, we’d need a second study looking at 8-12 rep sets versus 20+ reps.

Thankfully, two years later, researchers from McMaster University, Canada, gave us that second study. (2)

This time, one group of subjects performed three sets of leg extensions with their 8-12 rep max while another group performed three sets using their 20-30 rep max over a ten week period.

The trial was published in the Journal of Applied Physiology, and it noted that both groups increased muscle size by around 7% overall.

This study was the first of it’s kind to clearly show that high rep training was just as effective for building muscle as low rep training.

high reps or low reps

how many reps to build muscle
Dance teacher Phoebe blasts another 25 rep set in the gym.

Why It Works

Let’s science this s**t up.

Our muscles are made up of two very different types of muscle fibers.

We have weaker fibers which possess greater endurance (known as slow twitch muscle fibers), and we have bigger, significantly more powerful fibers which have very limited endurance (known as fast twitch muscle fibers).

When we perform heavy, explosive moves we train our fast twitch muscle fibers more.

Most guys want to hit those fast twitch fibers because, after all, they’re the ones which have the largest potential for growth.

But the real “secret” lies in hitting both types of muscle fibers!

To understand why, we need to take a quick look at how the human body works.

Your body’s primary function is to keep you alive. It doesn’t care what you want to look like, or how you want to perform in the gym. It only cares about sustaining life. So it’ll try to make every task as easy as possible, in order to maintain that status quo.

Let’s transfer this into a gym scenario.

high reps benefits

When you pick up a heavy weight, the body looks to do as little work as possible in order to get the job done, so it begins recruiting muscle fibers from smallest to biggest.

Curl a heavy dumbbell, and your slow twitch fibers (the small, weak fibers) are the first to be called into action. They will quickly realize they are no match for the weight involved and they’ll bail out on you, as the fast twitch fibers (the bigger fibers) take over.

If the weight is still too heavy, all of the remaining fast twitch fibers in the muscle being worked are also called into action, and you eventually get the weight up. You keep doing this until you reach the end of your set, or until you are unable to perform another decent rep.

Of course, this all takes place in a split second, but now you have some perspective as to what’s actually happening inside your muscle cells as you perform a set of dumbbell curls.

high reps vs low reps

The problem here, however, is that your fast twitch muscle fibers have been worked hard, but your slow twitch fibers have not been worked at all. Remember, they bailed on you the second the going got tough!

Let’s try this again, but this time we’ll use a weight which allows us to push out 20-25 reps…

Once more, our biceps are going to recruit muscle fibers from smallest to biggest. Our slow twitch fibers are the first to step up to the mark, only this time they can handle the stress of the weight, at least for the time being. Once they fatigue, the cavalry is called and our fast twitch muscle fibers take over again.

If you’re using a weight which causes you to “fail” (i.e. being unable to perform another good rep) at around 20 reps, you will have just worked both types of muscle fibers extremely hard.

And that’s why high rep training is so effective!

But that doesn’t mean you should exclusively do high rep sets.

I often have my clients either go through phases of low reps and high reps, or mix the two regularly, to get the most from both types of training.

See, if I can refer you to my bullet points above, you will notice that training in the 8-12 rep range will yield more strength gains than going higher in reps. It makes sense that unlocking those additional strength gains will then help you move heavier weights in future, which is great news for even more results.

Variety is the key to success!

As an extra benefit, utilizing high rep training will also enable a temporary increase in the production of growth hormone, as a by-product of the lactic acid which forms in our muscles during those intense, burning sets, adding another ace up your sleeve.

does low reps make women bulky

Should Women Do High Reps?

If you’re a girl reading this, you’re probably panicking…

Because for years you’ve been told to “stay away from heavy weights”, so you don’t bulk up and look like The Hulk in a prom dress.

Now, if high reps will build just as much muscle as low reps, what the f**k are you supposed to do?

Well, the first thing this shows you is that the whole “weights will make you bulky” thing is complete bulls**t.

The female body releases way less testosterone that the male body, which makes it significantly harder for women to build muscle. In order for a girl to build a large amount of muscle (i.e. to look like a bodybuilder), she’d need to be eating a significant number of calories per day and injecting good old “vitamin S”…

how many reps should women do

Just like guys, women should be training both types of muscle fibers!

If anything, today’s interesting research should have persuaded you not to be afraid of lifting heavier weights and visiting the lower rep ranges on your sets from time to time. After all, they are scientifically proven to build the same amount of muscle as the rep ranges you are probably using right now.

About 80% of my personal training clients are female, and all of the girls I train utilize both high reps (20-30 reps per set) and low reps (5-12 reps per set).

All of them perform big compound lifts (squat, barbell row, bench press, deadlift, clean and press, etc).

And the next time some fitness instructor tells you to stick to light, fluffy dumbbells and perform endless cardio, you definitely have my express permission to tell them to suck it.

high reps and light weights to tone up

High Reps Doesn’t Mean Light Weights

When people hear high reps, the sometimes link it with light weights.

That shouldn’t be the case.

It stems from the myth that “you should do high reps with light weights to tone up…”

I hate the phrase tone up.

So while we’re in the process of busting gym myths, let’s add this one to the pile.

Your muscles are only able to do two things: grow or shrink.

That’s it.

They can’t “tone.”

They don’t even know what that word means.

How “toned” you look ultimately depends on how much body fat you are carrying, nothing else. And if you’re not training hard enough (i.e. using weights that are too light), you aren’t going to drop body fat.

So high rep training shouldn’t be easy. You should treat it the same as you treat low rep training – use your rep target as a guide, with the ultimate goal of creating muscle failure.

If your target number of reps in the upcoming set is 25, the final five reps should feel as excruciating as a Nickelback concert.

This way, we are achieving true muscle failure.

There are studies out there clearly showing us that training a muscle to failure leads to superior hypertrophy than training with a weight you can comfortably handle.

One of the most notable studies was referenced earlier in this very article, when researchers from Canada in 2010 compared the effects of a 4 rep max versus a 25 reps max.

The high rep group were able to push their muscles significantly closer to muscle failure, therefore yielding a greater anabolic response from the training.

Another study, this time published in the Journal of Nutrition, again compared the effects of using a 4 rep max weight, a 25 rep max weight, and a 25 rep non-max (i.e. the third group could have continued going beyond 25 reps). (3)

high reps or low reps

They came to the exact same conclusion – training to muscle failure leads to greater results!

Again, this is because a lot of those results come from the fact we are fully exhausting the muscle by forcing our body to recruit more muscle fibers, releasing more lactic acid and growth hormone.

So don’t use an “easy weight” for high rep sets. Use as much as you can lift with proper technique, chase down “the burn” and embrace the damn pain. That’s where all the results are!

You’ll notice that I often mix up traditional low rep training with high rep work in my online training plans. Now you know why!

If you’ve enjoyed today’s article “Should You Do High Reps Or Low Reps?”, share it socially so others can check it out and get past these same issues with their own training. If you found it helpful, someone else will too. Plus, it’ll make you look smart as f**k.

should you do high reps or low reps

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