Another Muscle Intelligence blog coming to you from Team BPI athlete and expert trainer, Tyrone Bell.
“Let’s talk about the pump. Does it play any real, critical role in enhancing your lean muscle building efforts? You know what I’m referring to: that feeling during a workout where your muscles feel so engorged with blood, so full, that it feels like your skin is going to split. That’s the pump.
Apart from looking awesome and helping you feel swole, how does the pump benefit hypertrophy and physique structure change in the long run? Well, where the pump becomes anabolically effective is in its pairing with a physiological response known as muscle cell volumization. It’s the swelling of the cell that works as a mechanism for muscle growth.
First thing we need to understand is that while the muscle pump and cell volumization are closely related, and work hand in hand, they’re not the same thing. Muscle cell volumization refers to the actual volume of H2O inside the muscle cells. The pump refers to increased volume in between and surrounding the muscle cells. In spite of them being different, obtaining a pump is required to bring about increased cell volume.
Before we dive in and start breaking down the physiological process of both, let’s talk about why it’s important. Why would you want to know how the pump and muscle cell swelling actually work? Understand that cell volumization is, first of all, critical for the shuttling of amino acids into your muscle cells. It’s critical in triggering the body’s new lean muscle process, known as protein synthesis. Additionally, it helps suppress protein breakdown, especially during training and immediately after. Muscle cell volumization and muscle pump are two of the most anabolic responses your body has. Got your interest? Good. Let’s have a look at how this all works.


In response to high-intensity training, dilation occurs, increasing blood flow to the working muscles. This enhances the delivery of oxygen and nutrients to the muscles, as well as increases the plasma and H2O around and between the muscle cells. Boom! We have ourselves the pump. But what about cell swelling? Do we have that?
Well, it may come as a surprise, but it’s the processes required to bring about the muscle pump that actually, at first, set your muscle cells up for cell shrinkage rather than volumization. But fear not. Your body has this under control. Through regulatory volume increase, your skeletal muscle cells are able to not only maintain cell volume, but even increase in volume. It does this through a number of processes that involve pumping sodium ions out of the muscle cells in exchange for pumping potassium in. This ultimately results in an increase in intracellular concentration.
As intracellular concentration increases relative to the fluid concentration outside of the muscle cells, extra water is pulled into the muscle. Boom! We now have muscle cell volumization. It’s critical to point out that these processes of shifting sodium and potassium in and out of your muscle cells are also critical for amino acid uptake into your trained muscles. To kickstart the lean muscle growth and repair processes, you need to get amino acids into your just-trained, damaged muscle cells. Amino acid uptake is increased by muscle cell volume and dependent on the sodium concentration induced by the sodium/potassium pump processes acquired in achieving muscle cell volumization.
Now that we have a brief understanding of how things work and know the importance of obtaining cell volumization during your training sessions, let’s look at a number of ways you can enhance and benefit further from the anabolic effects of muscle cell swelling.


At the most beginner level, proper hydration is needed for optimal cell volume. The ability to achieve protein synthesis and have it in favor of a protein breakdown during your training period is dependent on achieving this. If you’re even a little dehydrated, your body’s ability to achieve the desired muscle cell volumization will be seriously impaired.


In order to get water inside your muscle cells, and increase cell volume, maintaining optimal levels of sodium and potassium are critical. As we briefly discussed, sodium and potassium are required for cell volumization and amino acid uptake. Don’t be scared to add sodium and potassium to both your pre- and post-training nutrition. Understand that if your sodium is depleted, the pump you’re going to get while training will be weak at best.


Creatine monohydrate is really like the “magic pill” when it comes to obtaining muscle cell volumization. Creatine supports cell volumization in a couple of ways. First, it directly helps by pulling additional water into the muscle cell. It also helps cell volume by helping to provide the energy source ATP, which is required by the muscle cell when it’s moving sodium outside of itself during that sodium/potassium pump exchange. Five grams of creatine before or during your training and five grams immediately after training will work nicely to assist muscle cell volume.


The last point I want to discuss isn’t from the point of view of obtaining cell volumization, but rather, maximizing its effects once you have it. It’s all about placing mechanical tension and stress on a pumped up, volumized muscle – that’s where the real effects happen. Part of the mechanism by which muscle cell swelling triggers muscle protein synthesis is via increased tension on the muscle itself. This external load placed on the muscle directly increases protein synthesis. In addition, forcing muscle contractions under substantial load when the muscle is volumized activates amino acid uptake.
Make sure that the program you’re following takes this into account. A program structure that takes you through a muscle activation, then target muscle pump and then a shift of focus on mechanical tension. This is a good place to start to maximize muscle cell volumization and anabolic effects.”
All readers are advised to consult their physician before beginning any exercise and nutrition program. BPI Sports and the contributors do not accept any responsibility for injury sustained as a result of following the advice or suggestions contained within the content.