Hypertrophy vs Strength Training: What’s the Difference?

If you want to know the difference between hypertrophy training and strength training, what they have in common and where they differ, then give me a few minutes and I’ll explain more about it in this article.

What prompted me to write this was an email I got the other day. It said:

“I’m really confused about the difference between hypertrophy programs and strength gain programs. I understand hypertrophy means mainly size gains and strength is obviously strength gains, but I thought mostly everything included both of them, making strength AND size gains. What’s the difference between programs that are designed for one but not the other?”

Hypertrophy vs Strength Training: What’s the Difference?

The goal of training for hypertrophy is to increase muscle size, while the goal of training for strength is to maximize the amount of force those muscles can produce.

In general, a bigger muscle is a stronger muscle, and there is a degree of overlap between the two training methods. 

That is, a hypertrophy training program will do more than just make your muscles bigger. It’s also going to make you stronger. On the flip side, one of the side effects of a strength training program is an increase in muscle size.

It’s not like a strength training program will generate strength gains but no hypertrophy, or that a hypertrophy training program will lead to bigger muscles with no increase in strength.

However, doubling the amount of weight you’re able to lift in a given exercise doesn’t mean that the muscles involved in lifting that weight have doubled in size. Nor does it follow that increasing the size of a muscle by 50% will produce an equivalent gain in strength.

What’s more, gains in strength tend to outstrip gains in size when you first start lifting weights. Put differently, you’ll get stronger far more quickly than you gain muscle. That’s because not all of those strength gains are driven by an increase in muscle size.

In fact, when you’re just starting out, the link between changes in strength and changes in size is relatively weak. Over time, hypertrophy makes a progressively greater contribution to strength gains, and the relationship between the two becomes that much tighter.

How Strength Training Makes You Stronger

One of the ways strength training makes you stronger is by increasing the size of your muscles. Strength is the ability to produce force, and a larger muscle fiber will generally produce more force than a smaller one.

However, there are multiple factors other than hypertrophy that can influence strength gains, from an increase in tendon stiffness to changes in the activity of your nervous system.

The relative contribution each one makes to changes in strength will depend on the type of training you’re doing, as well as how strength is being measured.

In short, there’s a lot that contributes to strength beyond an increase in muscle size, and maximizing the speed at which you gain size or strength will require different approaches to training.

Hypertrophy vs Strength Training: Sets, Reps and Rest Intervals

A strength training program will typically revolve around lifting heavy weights. And by heavy, I’m talking about sets of somewhere between 1 and 8 reps.

Training for hypertrophy, on the other hand, can involve a variety of loads, ranging from light to medium to heavy.

You can do sets of 5, 8 or 25 reps. As long as you train hard and push yourself, all will stimulate a similar amount of growth. However, it’s the heavier sets of five that will lead to faster strength gains.

How long should you rest between sets?

In days gone by, it was common to recommend short rest intervals between sets (30-90 seconds) for hypertrophy, while training for strength involved longer rests, somewhere in the region of 3-5 minutes.

The idea behind using short rest intervals revolved around increased levels of metabolic stress and a superior hormonal response to training, neither of which are as important for muscle growth as was once believed.

RELATED: The Myth About Squats, Testosterone and Muscle Growth

In fact, most of the research out there to compare short (60 seconds or less) with longer (2-3 minutes) rest periods shows superior gains in both size and strength with the latter [1, 2].

Why do longer rest intervals work better?

As the rest intervals go down, the accumulation of fatigue goes up. This limits the amount of weight you can lift, and the number of reps you’re able to do. As a result, the strength of the muscle-building stimulus generated by a given workout is weakened, and muscle will be built more slowly.

“Lifters who maintain a very short rest interval in order to ‘get a pump’ are ultimately short changing themselves when it comes to hypertrophy,” explains Lyle McDonald. “A sufficiently high tension stimulus is required for growth and short rest intervals prevent that. Not only do they not help growth, they tend to actively harm it.”

Hypertrophy vs Strength Training: Exercise Selection

Most strength training programs also center on a relatively small number of compound lifts, most notably the squat, bench press and deadlift.

That doesn’t mean you do only those exercises and nothing else. An effective strength-training program will also include a number of accessory/assistance exercises based on the needs and goals of the individual.

But the squat, bench press and deadlift are typically the “big rocks” that go into your training bucket first.

Training for hypertrophy, on the other hand, usually involves a much larger range of exercises, which leads to more complete development of a muscle group.

The quadriceps, for example, is made up of four different muscles – vastus medialis, vastus lateralis, vastus intermedius and rectus femoris. And squats primarily work three of them. The fourth, rectus femoris, takes a back seat.

In fact, when Japanese researchers used MRI scans to measure changes in muscle size after 10 weeks of squatting, three of the four muscles that make up the quadriceps grew by around 5%  [3]. Rectus femoris, on the other hand, didn’t grow at all.

If squats are the only leg exercise you do, some parts of your quadriceps won’t grow as quickly as they would if you did additional exercises like the leg extension [4, 5]. In fact, three months of leg extensions saw rectus femoris grow more quickly than the other three muscles in the quads [6].

If your main goal is to get stronger, and you’re not too bothered about maximizing the development of this or that muscle group, there isn’t so much of a need to include a variety of exercises in your training program.

Final Thoughts

There is a link between size and strength, and a training program focused on one will usually lead to an improvement in the other. However, hypertrophy is not the only factor that contributes to strength, and maximizing the speed at which you gain size or strength will require a different approach to training, most notably a focus on training with heavier weights and lower reps.