Benefits of Higher-Rep Training (8-12 reps)
Less Neurologically Demanding: When conducting higher-rep sets, trainees can generate a high-volume output with fewer sets and a lighter load. This shortens the workout and decreases the session's overall degree of difficulty, making the trainee less susceptible to overtraining. When training with lower-reps, a trainee must perform more sets at a greater intensity to maintain the same volume output. This is extremely taxing to the central nervous system and most trainees won't be able to perform such demanding workouts for extended periods of time without frying their nervous systems.
Greater Density per Workout (work per unit time): When working in higher-rep ranges, trainees will be performing fewer total sets and will generally be resting for shorter periods of time than when training in lower-rep ranges, thus increasing the density of the workout. Density is a critical variable in the muscle building equation.
Greater Time Under Tension per Set: Given equal tempo prescriptions, higher-rep sets will yield a greater TUT per set than lower-rep sets.
Benefits of Lower-rep Training (<6 reps)
Greater Protein Degradation per Rep: When training with lower-reps, trainees can use much heavier loads than when working in higher-rep ranges. Heavier loads place greater tension on the working muscles, which will in turn cause greater protein degradation per rep. The amount of protein degraded during an exercise session is directly related to the growth potential of that session.
Greater Functional Growth: Substantial growth of the contractile proteins myosin and actin can be attributed to low-rep training, while higher-rep training tends to yield more sarcoplasmic hypertrophy. This is known as "functional" vs. "nonfunctional" growth, as the former yields substantial increases in strength, while the latter does not.
Greater Strength Increases: This is partly due to the contractile hypertrophy mentioned above, but neurological factors also come into play. Heavy training is much more neurologically demanding than higher-rep work and an increase in motor neuron efficiency will also contribute to strength gains.
Greater Improvements in Myogenic and Neurogenic Muscle Tone: Because the contractile proteins are by far the densest component of skeletal muscle, one's myogenic tone, or muscle density, will be improved while on a lower-rep protocol. Also, one's neurogenic muscle tone (tone when movements or contractions occur) will be enhanced through the high-intensity induced sensitizing of alpha and gamma motor neurons.
Mais rien de nouveaux sous le soleil.
Ca devient ennuyeux la muscu ! Plus de théorie à débattre ! :-)