ABSTRACT: CELLULAR SWELLING, OFTEN REFERRED TO AS “THE PUMP,” HAS BEEN SHOWN TO MEDIATE INCREASES IN MUSCLE PROTEIN SYNTHESIS AND DECREASED PROTEIN DEGRADATION. THIS PAPER WILL EXPLORE THE POTENTIAL HYPERTROPHIC BENEFITS ASSOCIATED WITH THE PUMP AND DISCUSS PRACTICAL IMPLICATIONS FOR RESISTANCE TRAINING PROGRAM DESIGN.
Alex’s Notes: “A tight feeling… like somebody is blowing air into your muscles… it feels fantastic.” Those were the words of Arnold Schwarzenegger as he described what bodybuilders have called “the pump.” The pump represents an increase in intracellular hydration that causes the muscle to swell, resulting in a transient hypertrophy. No doubt resistance exercise has been shown to alter the water balance of muscle fibers, mainly because during intense muscular contractions the veins removing blood from the muscles become compressed, while the arteries continue to supply blood. Mechanical overload and tension are vital to promoting muscular hypertrophy, but there may be specific benefits associated with the pump as well. I mean, bodybuilders have been chasing it for years, and they are pretty big.
Cellular hydration is a regulator of cell function, and acts to increase protein synthesis while decreasing protein breakdown. These effects have been shown in numerous types of cells but the underlying mechanism is still somewhat of a ghost. One hypothesis is that the increased pressure pushes against the cell membrane, which is interpreted as a threat to integrity, and results in a response that works to strengthen the cell ultrastructure. It may also act through satellite cell activation.
So how do you maximize the pump? Well, you need to work hard enough to compress the veins and long enough to allow blood to pool within the muscle. The tension also needs to be constant so as to prevent blood from escaping. The easiest way to do all this is to use repeated medium-repetition sets and short rest periods. In other words, 5-10 sets of 8-12 repetitions with 30-60 seconds of rest. Keep in mind that this is assuming no other training is performed. If you are doing additional sets in a lower repetition range then these sets can be reduced.