How To Maximize Your Pump
Without a doubt, one of the more satisfying outcomes from intense weight training is the surplus of blood that rapidly fills your muscles as you train. This phenomenon, known as cellular swelling, or more commonly as “the pump” creates a euphoric feeling primarily because it provides a considerable, albeit temporary, increase in size of the muscle being trained— giving a sense of accomplishment that strokes the ego just a bit.
However, a deeper look into this phenomenon shows that the pump is more than just a short-term increase in muscle size and boost to your ego. According to several studies, the pump actually stimulates long-term adaptations within the muscle, promoting substantial gains in size and strength.1 Consequently, a better understanding of what causes the pump can be used to design a more effective training protocol that induces a superior muscle pump for greater gains in muscle mass and strength.
What Causes the Pump
The muscle pump occurs when the veins that are taking blood away from the working muscles are occluded by the contracting muscle tissue, while the arteries that bring blood to the muscle remain unobstructed. This creates a greater influx of blood into the area that causes blood to pool in the obstructed veins. This pooled, venous blood flows into capillaries connected to these veins, where it then leaks out of the thin-walled capillary and into the muscle cell, causing it to swell or “pump up.”5
1) Continuous Muscular Contraction
The optimal pump is achieved by a persistent muscular contraction, intense enough to occlude venous blood flow over a considerable period of time. The greater amount of muscular contraction time facilitates the pooling of more blood within the muscle for a better pump
Training methods that increase muscular tension on the vein, which maximizes occlusion, promote a better pump. In fact, increasing the amount of time the muscle is under tension by performing the exercise in a more continuous, nonstop manner minimizes muscular relaxation, which effectively increases muscular tension for greater inhibition of venous blood flow. The capacity of this lifting style to induce venous occlusion was shown in a study by Tanimoto et al.6, where they demonstrated that low-intensity knee extensions with no rest phase induced venous occlusion— which decreased muscle oxygen levels more effectively than a second group performing higher-intensity knee extensions with a one-second rest period.
Furthermore, a second study by Burd et al.7showed that a pump-inducing approach also increases muscle protein synthesis. In this study, a group of men performed leg extensions at 30 percent of their one-repetition maximum, with the concentric and eccentric portions lasting either six seconds or one second. Post-exercise muscle biopsies showed the slower leg extension movement had a greater increase in muscle protein synthesis, indicating that the more continuous six-second repetition enhanced venous occlusion for a greater pump that stimulated muscle protein synthesis.
2) Kaatsu Training
In addition to muscular contraction inhibiting venous blood flow, there is another very potent way to occlude venous blood flow. This somewhat unorthodox technique, known as Kaatsu training, involves wrapping either elbow or knee straps just above the trained muscle to occlude venous blood flow from that muscle. For example, if you are training biceps, securely wrap an elbow strap at the very top of your upper arm or if you’re training the quadriceps, wrap knee straps at the top of your upper leg. Also, make sure not to wrap too tightly as this would also diminish arterial blood flow into the muscle, reducing the impact on the pump— not too mention the inherent danger of cutting off the blood supply to working muscles.
Although restricting blood flow may sound unsafe, this type of training is very safe and very effective at increasing the pump when performed correctly. There has been an abundance of data showing that Kaatsu training stimulates considerable muscle growth and strength likely, in part, because of its ability to stimulate an incredible pump.8-10
3) Higher Reps With Less Rest
Weight training that relies heavily on anaerobic glycolysis for muscular energy production further enhances the intensity of the pump. This happens because anaerobic glycolysis, as the name implies, burns glucose within the muscle cell for energy without the use of oxygen. Anaerobic glycolysis produces an abundance of the metabolic byproduct lactic acid within the muscle cell, which tends to draw more fluid into the muscle, which enhances the pump.11,12
Training approaches that maximize this effect typically produce quite a pump. In general, very high-repetition sets combined with short rest periods accomplish this rather well. For instance, performing two exercises in a row, or supersetting, with the same body part using a 12-to-15-repetition range for several sets, generates plenty of lactic acid that will support a tremendous pump.