Thread: Sarcomere Vs Sarcoplasmic Hypertrophy

It is said that sarcomere hypertrophy is best stimulated in 6-8 rep range while sarcoplasmic hypertropy in 10-15 rep range.

Casey Butt, in his article, states that sarcomere tissue makes up %80 of muscle. So when you stimulate sarcomere hypertrophy you get more muscle mass.

If so, why do bodybuilders usually work around 10-15 rep range but not in 6-8range?

Originally Posted by Florian

Will you tell me more? Im new :/

All right.

Myofibrillar hypertrophy, mostly contractile material, is responsible for most of your growth. It's still unclear how much sarcoplasm can actually grow AFAIK. Working at high rep ranges (12-20) will stimulate relatively little hyperthrophy, mostly sarcoplasmic. Most bodybuilders use rep ranges of 6-12, because that's where, generally speaking, most of the hypertrophy results from.

However, it's not all about the rep range. Total volume is much more important. You need to not only stimulate, but only fatigue the muscle fibers. But stimulation increases by increasing the intensity (%1RM). Then there is Time Under Tension (TUT), which is at least as important as number of reps (reps x rep cadence). To make matters even more dynamic, there are two types of muscle fibers: slow (I) and fast (IIa/b) twitch.

Another important aspect is periodization. You can't keep stimulating the highest bang for your buck aspects (TUT, volume) of training, because your body adapts to the stressors placed on it. You'll need to find different ways to stress your body each period.

That's the tip of the iceberg, but I hope you catch my drift: it's not as linear as 7 reps => highest sarcomere stimulation => most hypertrophy.