There are some people who claim that they are getting a great “pump” at every workout but are still not gaining any any muscle (or gaining it slowly). While this can be due to numerous things of course, one thing should be made clear: Getting a pump should not be the goal of your workout.
First, let me explain exactly what a “pump” is: Simply, Lactic Acid (L-Lactate) is produced from pyruvate acid, which is produced from metabolizing glucose from your glycogen storages during exercise. (Whew! Just remember that your body makes lactic acid, a waste product, when you lift).
The lactic acid then flows into your blood stream so that it can be removed. However, when lactic acid concentration exceeds the body’s ability to remove it, your muscles start to swell up from the build up. A common misconception is that this lactic acid build up is responsible for DOMS (delayed onset muscle soreness), but it is not. The soreness comes from the micro-tearing of the muscle fibres.
So basically, the “pump” is a waste product coming out of your muscles with your body unable to remove it fast enough. The reason this should not be aimed for is that light weights moved slowly with reps of about 15-20 per set can produce big pumps in some people, but this will not be optimal for muscle growth.
Also, as someone’s VO2 Max improves (as they can more aerobically fit), they will become better and better and getting rid of the lactic acid that builds up in their muscle. However, this will not decrease the quality of the workout and may very likely increase it!
One last word: Some people like NO (Nitric Oxide) products and they say this is becuase it gives them a better pump. NO products do give you a better pump most of the time, but by now I hope you can see the actual reason why you might want to take an NO product:
“Nitric oxide is the muscle’s ‘cell-signaling’ molecule responsible for blood flow (hemodilation), oxygen delivery, glucose uptake, muscle velocity, power output, and muscle growth. (1)” It is the fact that some people get better and stronger workouts when taking NO preworkout; not the fact that it produces more lactic acid (it produces more LA becuase of the improved glucose uptake as described above).
Now you know that you should be focusing on your workout and not the pump. Try to improve how much you lift at least every two weeks while bulking (progressive overload).
P.S. If you are on diet that is very low in carbs, you may not be able to get a sufficient pump. This is becuase you might be glycogen-depleated, and so there is no glucose left to be (eventually) turned into lactic acid. This will most likely decrease the quality of your work out. If you are eating sufficient carbs, don’t always worry about the pump, espectially if you are performing a power workout as these do not produce as much lactic acid.