tuned up said:
its just that for me the range of 12 reps seems so much better-i get a better pump--but I know lifting more weight(hence less reps)has its positves too--which is best?
What I've found to work very well for myself and my clients is to periodize their training. That is, break your training up into short periods of time, say 6-8 weeks, and use different values for variable such as intensity (as a % of 1RM), volume, rest interval, frequency, exercise selection, etc.
As your intensity moves towards 100% of your 1RM the primary benefit leans more towards strength/power while the opposite direction illicits hypertrophy and ultimately more improvements in muscular endurance (< 30% of 1RM). Remember, as you increase your % of your 1RM you will decrease the volume (reps/sets).
For someone looking to increase overall mass it is not a bad idea to go through both a strength phase and a hypertrophy phase because:
1. A strength phase will increase the loads you are able to use at higher reps.
2. A hypertrophy phase is less taxing on the joints/soft tissue than a strength phase.
3. Changes in load, volume, RI, exercise keeps one's body progressing/adapting.
3. You will learn what works best for your body (provided you keep detailed records of your training).
There is no best way of doing things. You need to try various training methods to find which is best suited for your goals and your body. Periodization is just one way to keep things structured and may help you discover which method is for you.
Hope that helps.