Use both methods in different phases. When my training plateus after a couple months of hardcore heavy training I revert to lower weight with higher reps. For me I concentrate on intensity and pump through this phase and the body gets shocked in to action. You need heavy lifting for size and you need higher reps for density and shape and fullness. You will still pack on the weight through this phase. Eventually in my training I will do both heavy weights and higher reps in ths same workout. The rep range for high volume for me is between 12-20. heavy sets 4-8.

Hey mate they both have their place in training for size. I change my training from heavy 6-8 reps on upper body with 3 working sets and 2-4 movements depending on the muscle group being trained. When I notice that my motivation is declining or I am getting a bit stale I will change too German Volume Training. Here is a link that outlines it better than I ever could.http://www.muscleandstrength.com/articles/german-volume-training-for-sho... and another one http://www.simplyshredded.com/german-volume-training-a-new-look-at-an-ol... A way too look at this is not as high reps but at the total weight moved during your training session. Lets say for example that you max bench 140kg for 6. You have moved 840kg for that set. Then add up the amount of weight that you have moved for the duration of your training session. Now if you go and do 10 sets of 10 reps with 100kg on the bench you have moved a total of 10ton. Yep 10 000kg. You can't tell me that you wont grow from that. All that being said if you combine both types of training you can't go wrong. Thats from my experience.

I think its best to do both depending on week. say after 2 weeks of 8-12 reps, do a week of 5 and under then few weeks later aim for 20 reps. switch it up and keep your muscles balanced

My opinion is you should always train the main lifts heavy for low reps. Endless sets of high reps is eventually gonna stop paying dividends and you'll have to get stronger to build more muscle. I love working in the 3 to 5 rep range on squats, deads and presses. And then doing 10 rep assistance work like rows and what have you. I do not however consider myself a bodybuilder, and I do not train for hypertrophy only. My training focus is purely on strength. Because of this I don't have enough recovery for much on the assistance work, so you'll also have to find a little balance there to achieve your goals.

I do both bro, high for some exercises low for other. For instance arm night, sometimes i like to end it with a drop set til i cant lift my arms, some nights i like to finish as heavy as i can even if i end with 1 rep. Or even both same night. Test e or no test e best of both worlds all day brother cant go wrong. Foods whats gonna make you mass gain anyways