What is a Pump in the Gym & Does It Improve Muscle Growth?

If you’re interested in weightlifting, you’ve probably heard of “the pump.” 

It refers to the temporary increase in muscle size that occurs when you lift weights.

Bodybuilders have been strangely obsessed with gym pumps since people started lifting weights, and according to many, it’s the “secret” to unlocking rapid muscle growth.

Others are more dubious. They argue that “chasing the pump” is a fool’s errand because temporary muscle swelling has nothing to do with muscle growth.

Who’s right?

Are you doing something wrong if you don’t get a muscle pump?

And should you change your training to focus on pumping muscle if growth is a top priority?

In this article, we’ll dig into the research to provide evidence-based answers to all these questions. We’ll also unriddle other common queries, such as: What is a pump in the gym? Does a muscle pump mean muscle growth? How long does a pump last? And more. 

Table of Contents

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• What Is a Muscle “Pump?”
• How to Get a Pump
• How Long Does a Pump Last?
• Does a Muscle Pump Mean Muscle Growth?
• How to Use Pump Training to Build Muscle

What Is a Muscle “Pump?”

The “pump” is when your muscles temporarily look bigger after weightlifting, usually when you do a lot of reps with little rest between sets.

It occurs because your muscles produce metabolic byproducts like lactic acid when you lift weights, which contributes to the pump in a few ways:

1. Your body increases blood flow to the muscles to help remove these waste products, making your muscles swell.
2. These waste products draw water into your cells, making them larger.
3. The expanded muscle cells press on the surrounding veins, reducing the amount of blood that leaves the muscle.

The more muscle contractions that occur, the more these compounds accumulate, and the more your muscles swell.

How to Get a Pump

To get a pump, do the following:

• Do more reps in each set so your muscles produce metabolic byproducts faster than your body can shuttle them away.
• Take shorter breaks between sets, which keeps more waste products in your muscles.
• Do more sets, which further increases blood flow and metabolic byproduct production.

Now that you know how to get a pump, it becomes clearer why “pump training” centers around sets of 12-to-20 reps, with around 30-to-90 seconds of rest between each set (or less), for as many sets as possible (or until you get a pump).

Bear in mind, however, that a muscle pump fades fairly quickly. 

How long does a pump last exactly?

Let’s investigate.

How Long Does a Pump Last?

Once people understand what a muscle pump is and how to get a pump, a common follow-up question is, “How long does a gym pump last?”

The truth is, it doesn’t last as long as most would hope. 

Your muscles usually return to their regular size within an hour after exercising, and by two or three hours later, there’s no noticeable difference in your muscles’ size.

One way you may be able to prolong the pump is by using a pre-workout supplement containing l-citrulline.

L-citrulline widens blood vessels, improves blood flow, and can improve blood vessel health, which may help your pumps last longer. It also boosts your exercise performance, allowing you to do more reps per set and achieve bigger pumps.

Knowing how long pumps last leads to another critical question: does a muscle pump mean muscle growth?

Does a Muscle Pump Mean Muscle Growth?

Muscle pumps can lead to muscle growth, but it’s not the most efficient way to gain size. 

Research shows you can gain muscle without ever getting a workout pump. 

For instance, in one study that compared low-rep to high-rep training, scientists found that training with heavy weights in a low rep range was just as good, if not slightly better, for growth. 

In other words, there isn’t a huge difference in muscle growth between pump training and strength training. 

There are, however, practical reasons to prioritize heavy strength training:

1. When you train with heavier weights, you can generally progress (increase the weights you lift) more regularly, which is motivating. It also helps you gain strength more effectively, which becomes vital for gaining muscle as you near your genetic potential for growth. 
2. Lifting heavy weights feels less fatiguing, which can make workouts more enjoyable. For example, most people would prefer three 6-rep sets of squats over three 20-rep sets of squats, especially if you had to move on to other taxing exercises like the leg press and lunge. 
3. Sets of more reps take longer to complete and tax your cardiovascular system more than sets of fewer reps, forcing you to take longer rest periods to catch your breath. Together, this adds significant time to your workouts.

Should You Do Pump Training?

You may be thinking that pump training sounds like a waste of time, but that’s not entirely true—it has a few important benefits:

1. It helps correct muscle imbalances, which can develop if you only do compound barbell training. 
2. It adds variety to your workouts that helps keep training engaging and productive. 
3. The isolation exercises commonly used in pump training allow you to train your muscles at different angles and through various ranges of motion, which benefits overall muscle growth.
4. It can help you avoid injury by giving your soft tissues and joints a break from heavy weightlifting.
5. It emphasizes a muscle-building “pathway” called cellular fatigue more than low-rep strength training, which increases protein synthesis and decreases protein breakdown, theoretically resulting in more muscle growth over time.

This is why you generally want a balance of heavy, compound strength training and lighter, higher-rep exercises in your workout routine. 

A good rule of thumb is to spend about 80% of your time in the gym doing heavy strength training and the remaining 20% doing high-rep training.

How to Use Pump Training to Build Muscle

The key to maximizing muscle gain is incorporating strength and pump training into your workout routine.

While science has yet to pinpoint the perfect balance, top powerlifters, bodybuilders, coaches, and researchers typically use the following guidelines.

Prioritize strength training, but leave time for pump training. 

A good rule of thumb is to spend about 80% of your time in the gym doing heavy strength training and the remaining 20% doing pump training.

This is a good starting point for exposing your muscles to greater levels of tension through heavy compound lifting and more metabolic stress through pump training. 

I also how I personally like to organize my training, and it’s similar to the method I advocate in my fitness books for men and women, Bigger Leaner Stronger and Thinner Leaner Stronger. 

Do your heavy, compound weightlifting before pump training.

Studies show that you perform best on the exercises you do earliest in your workouts.

Since heavy, compound exercises are responsible for the lion’s share of your gains, you always want to do these at the beginning of your workouts.

Ensure you’re progressing in your pump training.

Like all forms of resistance training, pump training will only help you build muscle if you lift progressively heavier weights over time. 

Since you’ll be using higher reps, you’ll need to progress in smaller increments and may be unable to add weight every workout or week. But over time, you should lift more weight than you are now. 

Only use pump training on isolation exercises.

Compound exercises involve many more muscle groups and allow you to lift heavier weights than isolation exercises, so you generally get better results when you pair them with heavier, lower-rep training.

Isolation exercises involve fewer muscles, don’t allow you to lift as much weight as compound exercises, and are better suited to lighter, higher-rep training. 

Experiment with different forms of pump training.

To make training sessions more interesting, try several kinds of pump training. The three most scientifically proven are rest-pause training, blood flow restriction training, and drop sets:

• Rest-pause training: Rest-pause training involves performing a set to failure, resting for a short period, and then doing several mini-sets with the same weight.
• Blood flow restriction (BFR): BFR is similar to rest-pause training, except that you partially restrict blood flow from the muscle tissue by using bands or wraps around your limbs.
• Drop sets: You do drop sets by performing a set to failure, immediately reducing the weight, and then doing more reps until failure. You can repeat this process several times. 

All three methods produce a skin-splitting pump and increase the metabolic stress on the trained muscle group but cause little to no muscle damage, making them practical ways to do high volume training without hindering muscle recovery.