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Mechanisms of Myofibrillar Hypertrophy vs Sarcoplasmic
Posted: Wed Jan 21, 2026 2:30 am
by LatinoBulk
Looking into the latest literature regarding the fluid shift in muscle cells versus actual contractile protein accretion. Thoughts on the 2025 Roberts meta-analysis?
Re: Mechanisms of Myofibrillar Hypertrophy vs Sarcoplasmic
Posted: Wed Jan 21, 2026 3:15 am
by MedellinMuscle
The sarcoplasmic expansion theory seems more valid for high-volume trainees. Myofibrillar seems to be the primary driver in lower rep ranges.
Re: Mechanisms of Myofibrillar Hypertrophy vs Sarcoplasmic
Posted: Wed Jan 21, 2026 4:00 am
by AndeanLifter
Doesn't the sarcoplasmic increase eventually provide the energetic environment needed for further myofibrillar growth though?
Re: Mechanisms of Myofibrillar Hypertrophy vs Sarcoplasmic
Posted: Wed Jan 21, 2026 4:40 am
by TropicStrength
I think we overestimate the distinction in practical training. You rarely get one without a significant amount of the other.
Re: Mechanisms of Myofibrillar Hypertrophy vs Sarcoplasmic
Posted: Wed Jan 21, 2026 5:35 am
by CaliFlex
Check out the biopsy studies on elite bodybuilders vs powerlifters. The glycogen storage capacity differences are staggering.
Re: Mechanisms of Myofibrillar Hypertrophy vs Sarcoplasmic
Posted: Wed Jan 21, 2026 6:15 am
by LatinoBulk
Exactly, Sydney. The mitochondrial density also seems to shift depending on the specific mechanical tension applied.
Re: Mechanisms of Myofibrillar Hypertrophy vs Sarcoplasmic
Posted: Wed Jan 21, 2026 6:50 am
by MedellinMuscle
Wait, are we still citing the Schoenfeld papers for this or has the consensus shifted?
Re: Mechanisms of Myofibrillar Hypertrophy vs Sarcoplasmic
Posted: Wed Jan 21, 2026 7:40 am
by AndeanLifter
Consensus is shifting towards a hybrid model. It is not an "either/or" scenario.
Re: Mechanisms of Myofibrillar Hypertrophy vs Sarcoplasmic
Posted: Wed Jan 21, 2026 8:25 am
by TropicStrength
Does anyone have the full text for the Haun et al. follow-up?
Re: Mechanisms of Myofibrillar Hypertrophy vs Sarcoplasmic
Posted: Wed Jan 21, 2026 9:00 am
by CaliFlex
I will DM it to you. It covers the intracellular space measurements quite well.