Understanding Muscle Pumps: A Guide to Unleashing and Enhancing the Phenomenon

“The greatest feeling you can get in the gym or the most satisfying feeling in the gym is the pump.”

This is one of the many memorable quotes from Arnold Schwarzenegger in the 1977 critically acclaimed film, Pumping Iron.

Maybe you can relate to Arnold’s quote, or maybe you have yet to experience a muscle pump.

Either way, there is a symphony of physiological responses that happen during a muscle pump that not only feel good but are beneficial for gaining muscle.

This article breaks down the science of a pump, the benefits of chasing one, and how to achieve a quality muscle pump every workout.

What is a muscle pump?

A muscle pump is a phenomenon in which the muscles become so engorged with blood that it feels like your skin could tear.

The pump occurs during intense muscle contractions, in which the veins that remove blood from the working muscles close, while the arteries continue to deliver blood (1).

This forces the liquid portion of blood called plasma from the capillaries — small blood vessels that connect arteries and veins — into narrow spaces around your muscle cells.

As pressure builds, fluid or plasma is forced back into the muscle, causing cellular swelling, better known as the pump.

Bodybuilding-style training, which involves moderate-to-high repetitions (8 to 15) with short rest intervals (30 to 60 seconds), is usually necessary to experience a pump.

This style of training also creates an accumulation of waste products from energy production that draws additional fluids into muscle cells expanding them.

Muscle pumps can increase muscle growth

Although a muscle pump is thought to be a temporary phenomenon, research suggests it has lasting effects on muscle growth.

There are three primary factors suggested to trigger muscle growth — metabolic stress, muscle damage, and mechanical tension (1).

Of these, mechanical tension is believed to be the major trigger.

Mechanical tension refers to the tension or force created within muscles during resistance training or weightlifting exercises.

This tension signals various metabolic pathways that favor muscle protein synthesis — the process of building new muscle proteins — instead of muscle protein breakdown.

To increase tension and therefore muscle growth, you should gradually increase the weight, number of repetitions, or your training frequency over time.

This is known as progressive overload.

Like mechanical tension, cellular swelling or the pump — as a component of metabolic stress — may also trigger muscle growth by favoring muscle protein synthesis.

Though not fully understood, it’s suggested that muscle cells perceive a threat to their integrity in response to swelling, which initiates a signal to reinforce the muscle cell’s structure as a defense mechanism for survival (1).

Cellular swelling may also boost muscle growth by increasing the activity of satellite cells or muscle stem cells, which contribute to muscle repair and growth.

How to get a muscle pump

Whether you have yet to experience a pump or want to increase the quality of your pumps, there are a few things you can do.

Modify your training

Without exercise, there is no pump.

However, the type of exercise and how you train matters immensely.

Bodybuilding-style workouts offer the greatest opportunity for a pump since they focus on activating single muscle groups — usually one or two per workout — with a moderate-to-high number repetitions for each exercise.

For example, if you’re training your chest, you could choose 2 to 3 chest exercises and perform 3 to 4 repetitions of 8 to 12 repetitions for each exercise and rest 30-60 seconds between sets.

This type of training is sufficient to prevent blood from leaving the muscle while the arteries continue to deliver it.

Another approach to maximize your pump is to incorporate drop sets into your routine (2).

Start with a weight that allows you to complete 8-12 repetitions. Following that, without rest, transition to a lighter weight (around 25 to 50% less) and perform an additional set of 8-12 repetitions or as many as you can manage while maintaining good form. Drop the weight again and perform more repetitions until failure.

Finally, you can also do partial or half repetitions for certain exercises to focus on the portion of the movement that maximally stresses the muscle.

For example, performing half repetitions for the bench press and biceps curl is a better strategy for achieving a pump in the chest or biceps than a full-range bench press or biceps curl.

Of course, you don’t want to train using half repetitions all the time, but they could be a good strategy for finishing your workout with a strong pump. 

Take certain supplements

Certain supplement ingredients may help you achieve a pump quicker while also making it better or last longer.

Most of these ingredients increase your body’s production of nitric oxide, a potent vasodilator, meaning it relaxes the inner muscles of your blood vessels, causing them to widen.

In this way, nitric oxide increases blood flow and nutrients to your working muscles.

Arginine, an amino acid, is one of the most common ingredients found in preworkout products to increase nitric oxide.

However, as much as 38% of the arginine you consume is broken down before it has a chance to reach the bloodstream and produce nitric oxide (3).

A much better choice for boosting nitric oxide and achieving a quality pump is citrulline, another amino acid, which the body can use to make arginine and then produce nitric oxide.

Citrulline doesn’t undergo the same metabolism as arginine, and it inhibits the enzyme that breaks down arginine, making it a better choice for increasing levels of arginine and therefore nitric oxide than arginine itself (4).

PEScience’s Prolific Pre-Workout provides a generous 6-gram dose of citrulline, more than enough to get your blood flowing.

Nitrate is another effective ingredient.

It’s usually provided in supplements as beetroot powder or extract or as a salt.

Nitrate effectively increases nitrite concentrations — a marker for nitric oxide production — suggesting it’s well absorbed and available to the body (5).

Some products like PEScience’s High Volume Pre-Workout provide nitrate bonded to arginine, an effective way to reduce arginine breakdown while providing two potent stimulators for nitric oxide.

Other ingredients that may be useful for a pump include (6, 7, 8):

  • Vitamin C: Vitamin C supports the enzymatic process that produces nitric oxide.
  • Magnesium: Magnesium supports the enzymatic process that converts arginine to nitric oxide. It also has vasodilatory effects.
  • Sodium: Sodium is necessary for muscle contractions, and helps increase blood flow volume.
  • Glycerol: Glycerol increases fluid retention, potentially aiding in maintaining fluid balance during exercise to help maintain a pump. 

The bottom line

The pump refers to a phenomenon in which an increase in blood — namely plasma — causes the muscle fibers to swell.

While its feeling is temporary, research suggests that chasing a pump can be a potent stimulator for long-term muscle gains.

To experience your first pump or improve the quality of your pumps, focus on bodybuilding-style workouts, add drop-sets to your routine, and finish your workouts with half repetitions that focus on the bottom half of the movement.

You can also experiment with different supplement ingredients that enhance nitric oxide like citrulline and nitrate to enhance the quality and potentially the duration of your pumps.


Gavin Van De Walle, MS, RD
Gavin Van De Walle holds a master’s degree in human nutrition and exercise physiology. He is also a registered dietitian. Gavin has a bias for the truth and aims to provide the public with the information they need to make educated and informed health decisions. His work has appeared in a variety of publications, including Healthline, Livestrong, the American Botanical Council, Underwriter Laboratories, Verywell Health, and many more.
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