Interesting article by Dan Ogborn at Strengtheory discussing how the use of EMG Amplitude is not a good indicator of muscle hypertrophy.
Photo credit to Adam Palmer of 9 for 9 Media
Over the past few years, the data indicating that low intensity training, when taken to the point of concentric failure, produces comparable hypertrophy to high load training has literally piled up. There’s a growing collection of studies in both trained and untrained individuals, considering whole muscle growth and that of specific fiber types, all of which demonstrate the comparable effectiveness of various training intensities to promote muscle growth (1-6).
Despite the growing collection of studies on our outcome of interest (hypertrophy), there’s still resistance to the idea that low intensity training (i.e. 30%-1RM) can be as effective as high intensity training for muscle mass (>65%-1RM). While there are studies that do not support our new-found understanding (7,8), much of the resistance stems from the idea that light weights do not recruit as much muscle as is required to move heavy ones (9).
If the idea that a muscle fiber must be recruited in order to adapt to training is true, then any stimulus that fails to stimulate a good proportion of the motor unit pool within a muscle would likely produce less growth than one that does. Score one for heavy weights, right?