Pump-style training (if one knows what they are doing) usually aims to train through fatigue and force enough blood into the muscle so that the muscle facia is stretched. I see many guys in the gym over the years that only do this kind of training. They do it month after month, year after year, because it feels good and they look good in the mirror - while at the gym. If they pump their muscles until they hurt they can leave the gym feeling like they have accomplished something. They are not getting their body composition (fat/lean ratio) checked, and so consequently they can lie to themselves that they are heading somewhere. They probably gained some size when they first started working out and so those results supply a positive reinforcement to continue the same style of training. Adding to this positive reinforcement are some big roid boys pumping away and posing in the mirror. They are huge so why not train like them? Big mistake.
If you look more closely at the big guys in your gym - MOST of them are lifting big heavy weights. If they aren't, they are doing 2x or 3x the reps u are doing. What I'm getting at is our muscles will only grow if they are subjected to ever-increasing intensity over time. This intensity is a factor of the WEIGHT and REPS you are lifting. That big guy may be doing only 100kg on bench (nothing special), but he may be doing (or be capable) of 20+ reps which equates to a rep max of 150kg+. Once you have achieved that initial gain phase, if you are training in a linear fashion (training 8-10 reps until you happen to be able to go up a weight) then it is highly likely that you will not have good results. Pretty quickly you take a month or longer to go up to the next weight. Thats a lot of wasted workouts!
The latest knowledge suggests that pump-style training is effective more on parts of the body that get a lot of use in normal activity - legs, arms, calves, etc. The suggested science is that the muscle sheath of these commonly used muscles is toughened and requires stretching and swelling to better enable hypertrophy. Using this knowledge combined with every increasing intensity suggests that arms respond well to drop sets (the fatigue, stretching factor). Because of this, it is especially important to ensure you achieve the full range of motion for triceps/biceps! German Volume Training (GVT) addresses this method of training.
Generally speaking, higher rep ranges 10-30 encourage better storage and utilisation of muscle fuel (hypertrophy), while lower rep ranges encourage more nervous system cooperation (strength) and hyperplasia (additional muscle cells). The first technique results in more visible size increase, but this muscle is more transient. Go on a diet and you will shrink like a prune. Strangely, people usually pick a single technique to focus on. It was ONLY when I incorporated BOTH methods (I learnt this by going to some advanced trainers), that I have had some really great gains (+4.5kg lean and -3kg fat in 10 weeks). It makes sense. If hypertrophy simply increases the size of your existing cells, you need to be creating ever more cells to include in this process (hyperplasia). I now train in 1 month cycles. At the beginning of the month I train primarily for a hypertrophy response (15-30) reps, and then I gradually increase the weight and drop the reps until I am training primarily for more contractile tissue (2-8 reps). This has the added benefit of giving your nervous system the 'heads-up' to prepare to lift heavier and heavier weights. The important thing is that your calculated rep max is always going up (ever-increasing intensity). Another thing to remember is that our bodies don't count reps. The hypertrophy/hyperplasia rep ranges are guides only. Repping until you reach a magic number of reps is probably the most limiting thing you can do for your results.
In summary my tips would be the following:
- Familiarise yourself with the 1 rep max formula. Train hard and to
failure in a variety of rep ranges. Try starting at about 65% of your
rep max at the beginning of a month and ending at 95%. This equates
to roughly 25 reps down to 2.
- Stretch and pump arms with more volume than other muscle groups (but don't forget to add more weight over time). Try 10 sets of 10.
- Raise the weight and drop the reps across your sets. Why? Fatigue has a lot more of an effect on volume than strength. You can usually keep your rep max across your sets fairly consistent this way, which maximises the intensity factor across your sets. I hit rep max pbs on my final set all the time.
Here is an interesting read referring to a journal article that I can't find!