The pump is the short-term sensation you get during training when your muscles fill up with blood faster than the blood can leave the area, making the muscles appear fuller and larger. It’s a tight, swelled feeling, often accompanied by an increase in vascularity. Pump workouts generally involve medium (8-12) or higher (13-20+) repetitions, supersets/trisets/giant sets, and/or brief rest intervals between sets. But is going after the pump really necessary for muscle growth?

For bodybuilding and physique athletes, I believe the pump is of substantial importance and is something to pursue. For strength athletes, the pump is less significant. If it’s experienced at all, it’s a by-product rather than something sought directly.

You’ll hear some strength coaches and functional training experts knock pumping workouts because they claim pumping is cosmetic only and emphasizes “form over function.” That may be true, but if you’re interested in bodybuilding or physique development, then maximum pump can be very beneficial.

Most bodybuilders and even most exercise physiologists would agree that workouts that produce maximum pump can provide up to 20-25% of the increase in muscle size. This comes from sarcoplasmic and mitochondrial hypertrophy and increased capillarization. Sarcoplasmic hypertrophy looks good and is beneficial to bodybuilders, but you do tend to lose it more quickly with de-training.

The pump has virtually nothing to do with increased myofibrillar hypertrophy – the actual fiber growth that’s responsible for 75-80% of the increase in muscle size. That type of fiber growth comes only from heavy training, which produces much less, if any pump.

Remember something, you can get a pump by dropping down on the floor and doing a few sets of push ups, but that doesn’t mean you are going to get permanent gains in muscle fiber size.

In his book, The Encyclopedia of Modern Bodybuilding, Arnold Schwarzenegger pointed out another benefit of the pump, the psychological effect. It feels good and is very satisfying to watch your muscles swell up and see the veins bulge right before your eyes in a matter of minutes. Arnold wrote:

“When you are pumped up, you feel better and stronger, and it’s easier to motivate yourself to train hard and achieve a high level of intensity. Sometimes you will walk into the gym and feel tired and lazy but you will get a fantastic pump after a few minutes of work and suddenly feel strong and energetic.”

A good pump can be a good indicator of an effective workout from a bodybuilding standpoint. The late bodybuilding guru and trainer of the stars, Vince Gironda, taught that a workout taken to maximum pump and then stopped before the pump began to subside was the optimal volume, tempo and duration:

“My own method would be to exercise until I noticed a pump loss,” said Vince. “I would then check back the number of sets and reps required to achieve this effect (noting the tempo and the amount of rest between sets). In this way I was able to calculate my personal exercise level.”

As important the pump might be for bodybuilders, the criteria that are more important than pump are progressive overload, intensity and of course recovery. Probably nothing is more important in bodybuilding or strength training than progressive overload. This means you must beat your previous workouts and increase the amount of weight you use in a slow, steady and systematic fashion (using periodization of course, because you can’t keep adding weight to the bar forever in a linear fashion).

Some of the best gains I have ever achieved came from combining heavy strength workouts using a 5-6 rep max on basic exercises, with maximum pumping methods such as supersets, short rest intervals and medium-high reps.

I also believe that pump workouts combined with strength workouts give the muscles a more “polished” look than low rep strength workouts alone. High rep workouts alone do little more than flush blood into the area worked and contrary to popular belief, high reps do NOT get you “ripped.”

The “ripped” look is mostly a matter of low body fat, but if body composition is equal, the trainee who has done both types of training will usually have a more “finished” look to his or her physique than the trainee who only does low reps with heavy weight. If you look at powerlifters and strongmen, you’ll notice that even the ones with low body fat usually lack the polished look that competitive bodybuilders possess.