Mechanisms of the Pump

by Dr. Jacob Wilson, Ph.D., CSCS*D

February 10, 2017


Let’s perform a quick experiment; grab yourself a balloon and helium tank and proceed by simply inflating the balloon. There are no tricks or gimmicks here, however as the balloon continues to inflate, what is happening? The overall volume of the balloon continues to increase which results in a final product that is much larger than beforehand. A similar phenomenon can be replicated within your muscles by lifting weights.

Much like the tools needed to inflate a balloon, the human body has the ability to experience a similar sensation by relating the balloon to your muscle cell, the air as your water concentration, the helium tank as your transport channels, and the string as your cell membrane. Much like a balloon before inflation, muscle cells are small and flat without outside stimuli. Achieving this is plausible through both specific training regimens or by consuming compounds which have the ability to increase fluid concentration within the cell causing “the pump”.

Cell Swelling


Cell swelling occurs due to your cells initial indication of a threat towards its integrity and in turn, promotes a process to further protect its structure. Through intense training, oxygen becomes less available by restricting your arteries ability to deliver enough blood to the muscle. This enhances the need for hydration within the cell which causes the muscle fiber to swell (Schoenfeld., 2013). Although short lived, this occurrence has been shown to increase the body’s ability to utilize protein for repair and building, ultimately increasing muscle mass!

You’re in the gym performing a workout and suddenly you push yourself to a new level, a level that brings with it an enticing experience which you have never felt. You feel as though your muscles are about to burst. Your first question becomes whether this is supposed to occur or if you are experiencing a health issue. Have no worry, this occurrence is far from negative and may promote muscle growth.

The Pump

A common question is how you can optimize the rate at which you experience “the pump”? This can occur naturally by incorporating specific workouts that manipulate different variables or by consuming different supplements which have the ability to promote your body’s ability to reach this stage quicker and for a longer duration. These are widely used for their ability to maximize your cells potential to draw more water into the cell and create an environment which promotes the cell swelling effect.

“The greatest feeling you can get in a gym, or the most satisfying feeling you can get in the gym is… The Pump. Your muscles get a really tight feeling, like your skin is going to explode any minute, and it’s really tight – it’s like somebody blowing air into it, into your muscle. It just blows up, and it feels really different. It feels fantastic.”
– Arnold Schwarzenegger


There are a number of different training approaches that can promote the cell’s need for more hydration and in turn lead to “the pump”. Including supersets is a great way to blast a specific muscle consecutively. This can include tri sets which include three different lifts back to back with no rest or even giant sets that contain four or more. Drop sets are a similar approach, however, instead of performing many workouts, you simply perform only one. After achieving your desired number of reps, immediately lower the weight substantially and perform the lift again.

These approaches simply imply performing more lifts with limited rest periods which creates the influx of hydration. Blood Flow Restriction (BFR) training is also a great mechanic used that limits blood flow by utilizing tourniquets or straps. This creates a way for blood to continue coming to the cell however unable to leave and go to other parts of the body. These are all great ways to achieve the pump and may be great tools to elicit muscle hypertrophy. I’m sure you are curious now with how one can achieve this sensation through supplementation.


As mentioned above, specific training programs can initiate this technique however certain compounds also can. By choosing a supplement that delivers more blood or hydration to the cell, you will optimize the cell swelling effect. Glycerol, commonly labeled as HydroMax, is an ingredient in many pre-workout drinks that contribute to just this. Fluid concentration in the cell is directly linked to Glycerol. The main determinate of these results is glycerol’s ability to rapidly change the movement of water across the cell’s membrane which creates a shock factor (Nelson., 2007).

Citrulline and arginine are two other supplements which are able to impact “the pump”. Citrulline turns into arginine, which has been connected with increasing Nitric Oxide (NO) levels, allowing for blood vessels to become further dilated, ultimately supplying the cell with more blood (Wax, 2015). L-Norvaline is another supplement that affects NO levels by inhibiting an enzyme which turns off NO production. By preventing this enzyme’s production, NO is able to be produced at a higher rate more consistently (Bommarius., 1994). These are just some of the many different supplements that aid in achieving an influx of fluid into the cell and result in cell swelling.


Generating the muscle pump is a great proposal to maximize time in the gym with relation to cell damage. These are just some of the mechanics and supplements you can implement in order to achieve “the pump”. Either approach will yield a feeling like no other. The take home message here is the greatest feeling in the world, explained by Arnold, is also extremely beneficial towards achieving muscle growth.