Updated: Sep 28, 2021
TL;DR: The muscle pump may play a role in promoting muscle growth, but it is a relatively small factor and won't make or break your workouts.
The following phrases; "the pump" and "muscle pump" is a term most bodybuilders, gym-goers and fitness enthusiasts have undoubtably heard of before.
The muscle pump is caused by the sudden influx of blood into a muscle, causing the muscle to swell and become bigger, this is something many people chase when going to the gym.
But does the muscle pump actually help build muscle?
I'll explain the science behind the pump in this article.
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One reason weightlifters like experiencing a muscle pump is because it serves as a visual indication that their efforts in the gym are paying off.
It seems as though your muscles are growing before your own eyes, even if it's temporary.
This obsession with the pump hasn't subsided in the meanwhile.
Some people even "chase the pump" which is bodybuilder slang for doing a high number of slow reps until your muscles are full and swollen.
There are some people who say that chasing the pump is worthless. Other people swear by chasing the pump, claiming that it builds muscle and strength.
But, who is correct?
Both are correct. You can effectively build muscle without the muscle pump, but it is also a useful addition to incorporate into your workouts.
Scroll down to see the role of the muscle pump in muscle growth and strength, and how to enhance it.
What Is the Muscle Pump
The term "muscle pump" refers to the temporary and rapid increase in muscle growth that happens when you lift weights, particularly when you train with greater repetitions, shorter rest periods and longer time-under-tension.
It occurs when you lift weights for an extended length of time.
When you're training and lifting weights, it causes changes in our muscles.
To understand why the muscle pump occurs, we must examine what happens within our muscles when we lift weights.
Why It Happens
When muscle fibres contract, it results in the accumulation of metabolic byproducts such as lactic acid inside, and around the muscle cells.
In a variety of ways, chemicals like lactic acid contribute to the development of the muscular pump.
Firstly, your heart pumps extra blood into your muscles in order to transport these chemicals out of your cells, causing your muscles to expand as a result of the rapid influx of blood.
Secondly, these chemicals draw water into the muscles cells, increasing the physical size of your muscle cells.
Thirdly, as the muscle cells grow in size, they put pressure on the blood vessels within the muscle, limiting the quantity of blood that is able to escape.
Below is an illustration showing part of the reason why a muscle pump occurs.
It is much easier for blood to flow between your muscle fibres when they are relaxed, allowing easy entry and escape of the muscle.
During their contracted state, they squeeze and put pressure on the surrounding veins and blood vessels that are attempting to return blood to the heart, making it harder for the blood the leave the muscle.
The net effect of this process is blood is pumped into your muscles quicker than it can leave them, causing the blood to stay within the muscle, providing you with the famed muscle pump.
As well, the more muscle contractions you do, the greater the accumulation of lactic acid in your muscle cells, and the greater the amount of cellular swelling that happens.
As a result of increased blood flow to the muscle, the pump causes a temporary growth and expansion of the muscles that are being worked out.
The muscle pump happens due to increased blood flow to the muscle, decreased blood flow out of the muscle and increased cellular water uptake.
There are other factors involved in the muscle pump such as hormones, blood pressure, diet, supplements and more.
Does the Muscle Pump Help Build Muscle?
Both yes and no.
There is still research needed to unravel the complicated mechanisms that are responsible for muscle growth, but it is apparent that pump training is an effective addition to your workouts in order to increase muscle growth.
However, chasing the pump alone is still not the most effective way, far from it actually.
There are multiple factors involved in muscle growth.
Those factors being the following:
There is another factor that is not well documented but the theory supports its existence, cellular swelling.
Each factor has an affect on muscle growth and there are various ways to utilise them.
Metabolic fatigue is a muscular reaction to intense activity in which the rate of ATP usage has outpaced the rate of ATP replacement.
This results in the burning sensation you feel when you have done many reps, it often leads to failure to contract your muscle anymore.
Mechanical tension is what is created within the muscle when it spends time under tension from an external load (for example; a dumbbell, kettlebell, etc).
Using a heavy load and executing exercises over a complete range of motion for an extended length of time creates mechanical strain within the muscle and its fibres.
Muscle damage is the micro-tearing of the muscle fibres caused by them being under tension from an external load, such as weightlifting.
This causes inflammation within the muscle, leading to muscle repair and long-term growth in the size of the muscle.
Muscle damage is responsible for DOMS (delayed-onset muscle soreness).
Cellular swelling in muscle cells is caused by the increased uptake of water due to a variety of reasons, including the production of lactic acid and increased influx of blood within a muscle.
Increases in muscle protein synthesis and reduced protein breakdown have been found to be mediated and enhanced by cellular swelling, often caused by the muscle pump.
Where Does the Muscle Pump Come In?
The muscle pump primarily increases cellular swelling, theoretically causing enhanced protein synthesis and reducing muscle protein breakdown.
However, this is only theory.
Below I'll discuss the real-world studies conducted on the muscle pump and its effect on muscle growth.
New research conducted by experts from the University of Central Florida showed that you may successfully grow muscle without ever feeling a pump throughout your workouts. (1)
In a randomised controlled trial, the researchers divided 33 resistance-trained males with an average age of 24 into two groups.
Participants in Group One exercised in the 10-to-12-rep range utilising 70 percent of their one-rep maximum (1RM), with a one-minute break between each set.
Group two trained in the 3-to-5-rep range at 90 percent of their 1RM, with three minutes of rest between each session.
Utilising a higher rep range with shorter rest periods resulted in more muscle contractions in a shorter period of time, resulting in increased muscle pump.
Group two who utilised fewer reps with a heavier weight and longer rest periods had less muscle contractions in the same time, reducing the effect of the muscle pump.
With another way of putting it, the first group engaged in pump type training, whereas the second group engaged in heavy strength training.
They performed the same exercises, completed the same amount of sets, and exercised the same number of times per week.
Researchers observed to ensure they maintained correct, consistent form and technique throughout the study.
A two-week preparation phase was also required for both groups in order for them to get acquainted with the exercises and to ensure that they all started the trial with about the same level of knowledge and experience.
The participants trained using a lower-upper split comprised of complex multi-joint exercises such as the following:
Incline bench press
They also incorporated isolation exercises such as the following:
Each participant trained the same amount of the times per week, which was 4 days.
It was shown that both groups developed about the same amount of muscle, with a slight trend toward larger increases in group two that utilised heavier weights.
The findings of additional research have corroborated this conclusion.
Overall, there isn't much of a difference between pump training and strength training when it comes to muscle development.
However, this is directly comparing the two types of training.
It does not take into account one type of training in addition to another type of training.
Should You Chase the Pump?
Pump training on its own likely isn't very effective for growing muscle.
Ever heard of the 80/20 rule? It means 20% of the work done results in 80% of the results.
Pump training is only an addition, it will not make or break your workout, I'll get this clear first and foremost.
However, there are two compelling arguments for prioritising heavy lifting over pump training.
Heavy strength training requires less time than pump style training.
You'll have to train with heavy weights at some point, meaning you may as well begin training with heavy weights now.
So, you should prioritise heavy, compound exercises over lightweight "pump" style exercises and workouts.
After all, heavy weights will cause more muscle damage and post-workout inflammation, leading to higher muscle growth.
Plus, training with heavy weights will also cause some level of muscular fatigue and mechanical tension as well as muscle damage, giving you the full set of factors involved in hypertrophy (muscle growth).
But does this mean you should forget about chasing the pump altogether? No, chasing the pump is a useful addition to your heavy lifting workouts.
It enhances the muscular fatigue and cellular swelling factor of muscle growth.
Essentially, it is the "icing on the cake" for your workout, optimising and improving the final few percentage points of muscle growth.
You shouldn't chase the pump as your primary workout; rather, add it to your heavy lifting workout for the optimal muscle building workout.
A lot of these "pump" training programs and workouts are basically useless on their own.
Sure, you use them as an additional workout, but not as your primary method of building muscle.
Only After Compound Exercises
Pump training should always be performed after heavy, multi-joint exercises.
In general, the exercises that you do first in each session will provide the most amount of development.
Given that heavy, complex exercises are responsible for the majority of your gains, you should always do them at the start of your sessions to maximise your results.
Improve on Your Pump Training
Make sure you're making improvement with your pump training as well.
In the same way that all other kinds of resistance training do, pump training will only aid in muscle development if you consistently attempt to lift bigger and heavier weights over time.
Because you will be doing more repetitions, you will need to advance in smaller increments.
You may not be able to increase weight to every session or even every week, but over time you should be able to lift much more weight than you are now able to.
Don't Chase the Pump on Compound Exercises
Pump training should be performed on isolated exercises rather than complex exercises.
Compound exercises, by definition, engage many more muscles and enable you to lift much greater weights than isolation exercises; thus, they should be performed in conjunction with heavier, lower-rep training.
When compared to compound exercises, isolation exercises involve fewer muscles and do not enable you to lift as much weight. As a result, they are better suited to lighter, higher-rep training.
Try Different Types of Pump Training
Try several types of pump training to see what works best for you.
If you want to spice up your exercises, you may experiment with various types of pump training to keep things fresh.
Rest-pause training and blood flow restriction training are two of the most popular and scientifically validated methods available.
It is possible to do several mini-sets back to back with rest pause training; blood flow restriction training is similar, but it also includes putting bands around your limbs to prevent blood from flowing out of the muscle.
When you do any of these exercises, you will receive a pump with little to no muscle damage, which makes them excellent methods of adding more volume to your workouts without creating excessive exhaustion or muscle damage.
How Do You Get a Pump?
There are many methods of getting a muscle pump, as listed below.
Blood Flow Restriction Training
Blood flow restriction (BFR) training is achieved by combining low intensity exercise with blood flow obstruction (occlusion).
This provides a huge muscle pump by significantly slowing and reducing the amount of blood exiting the muscle.
Ever had a blood test where they put an elastic band around your upper arm? It's the same thing.
Anything elastic, even a tight compression sleeve or bandage could work.
Caution: Only do this exercise for a minute or so at a time, use something elastic which is thick and not small or thin.
Eccentric training is the slow controlled reps on the negative (eccentric) portion of a rep.
It provides much greater time under tension than traditional reps.
Using eccentric training has the same effect as blood flow restriction training, it reduces how much blood can leave the muscle, causing it to swell up.
Eccentric training has the added advantage of being very effective for muscle growth.
Isometric training is similar to eccentric training but takes it a step further. Instead of lowering a weight gradually and slowly, you hold the weight in position at a fixed point.
This provides huge time under tension and constant contraction of muscle fibres. Muscle fatigue and cellular swelling are increased dramatically with isometric training.
You can read more about concentric vs eccentric vs isometric training here.
A super set is a group of exercises completed one after another, with no rest or pause.
For example; 8 reps of push ups followed by 8 reps of bench press followed by 8 reps of dumbbell flys.
It has the same principle and mechanism as all of the other types of pump training, less rest and more time under tension.
A drop set is very similar to a super set, except each set is done to failure followed by a set of reduced weight of the same or similar exercise.
For example; 12 reps of 12kg dumbbell curls followed by 12 reps of 10kg dumbbell curls.
Again, less rest and more time under tension, you're also taking each set to failure which helps in muscle growth.
A rest-pause set is essentially compacting one set into multiple mini-sets with minimal rest between sets.
For example; splitting a 12 rep set into 6 reps followed by a 10-15 second break, repeated for as long as you desire.
It is useful for increasing time under tension, increasing the muscle pump.
Wearing a jumper for the first few sets or training in a warmer climate can help increase your body temperature.
An increased body temperature can increase vasodilation and blood flow.
This results in an enhanced muscle pump.
Supplements to Boost the Muscle Pump
There are a variety of supplements which help improve the muscle pump.
Most supplements are either hydrators, vasodilators or a carbohydrate mix, or a combination of them.
Hydrators such as creatine and glycerol monostearate attract water into the cells, which as explains earlier, increases cellular swelling and the muscle pump along with it.
Creatine increases the ATP production and draws water into the muscle cells due to increase available energy.
Glycerol monostearate is a form of sugar, sugar also increases the water drawn into cells.
Vasodilators can enhance blood flow such as the following:
Other nitric oxide boosting supplements can also help to widen the blood vessels, improving blood flow to the muscle and therefore boosting the pump.
They help to promote smooth muscle relaxation and therefore vasodilation and blood flow.
Carbohydrates can help enhance the muscle pump, this is due to increase water uptake along with the carbohydrates in muscle cells.
Sugars and carbohydrates always prefer to be with water, this means when they are taken into cells they usually take water with them.
This increases cellular swelling, resulting in a better muscle pump.
To summarise all of this information, the muscle pump can help to build muscle when used alongside heavy, strength-based training.
There are multiple methods of improving the pump, such as utilising blood flow restriction, eccentric and isometric training, using super sets, drop sets and rest-pause sets can also help.
Hydrators such as creatine and glycerol monostearate, vasodilators such as l-citrulline, l-arginine and AAKG and carbohydrates can help enhance the pump even further.
Written by Billy White
Billy White is a qualified Kinesiologist and Personal Trainer. He is an aspiring bodybuilder, fitness enthusiast, and health and fitness researcher.
He has multiple years of experience within the fitness, bodybuilding and health space. He is committed to providing the highest-quality information.
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This evidence, scientific theory and experience based analysis of the muscle pump features 1 reference, listed below.
1. Mangine GT, Hoffman JR, Gonzalez AM, Townsend JR, Wells AJ, Jajtner AR, Beyer KS, Boone CH, Miramonti AA, Wang R, LaMonica MB, Fukuda DH, Ratamess NA, Stout JR. The effect of training volume and intensity on improvements in muscular strength and size in resistance-trained men. Physiol Rep. (2015, Aug) ✔
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