Hypertrophy: should we use low loads or high loads?

Other aspects:
– Velocity and exertion of the 39th rep of a 40 reps set (to failure) is about the same than the 4th rep of a 5 reps set (to failure). So you still need to get tired, even when using low loads.
– Given that total work volume is the key aspect for hypertrophy, e.g. 50 total repetitions using low loads vs. high loads, the training session will be shorter when using low loads, since rest periods will be shorter between sets.
– It all comes to the final goal desired. Do I want greater muscle cross-sectional area in order to increase force production, or just for aesthetic reasons? The two interventions will have different outcomes: (a) with the same total work volume, low loads won’t have the same impact on neural adaptations as high loads do, so increases in strength, power and speed will necessarily be different and (b) low loads/high repetitions involve different energy pathways, with greater emphasis on local muscle endurance.

When selecting the best method to maximize hypertrophic responses, we should analyze the following aspects, by descending order of importance:
(1) chronical and training age
(2) general population vs. athletic population vs. rehabilitation process
(3) sports requirements
(4) training supervision vs. individual training
(5) type of exercise selected
(6) desired training weekly frequency
(7) time available for each training session
(8) equipment available