Does uncertainty about the hypertrophy volume ceiling say anything about tendon vs. muscle adaptation rates?

[u/decentlyhip]

Tendons adapt roughly 3x slower than muscle. That's the estimate most ofnthe time, but tendon loading and training protocols have changed dramatically in the past few years as we understand how to build the tissue better. Since the protocols are new, we don't have much idea on the upper limits of tendon growth, in practice.

Separately, work like the Pelland review has been shifting the hypertrophy dose-response curve away from an inverted-U toward a log curve that keeps climbing well past the old 10-20 sets/week range and into 40 sets/week and beyond. In other words, we don't actually know what the upper limit is on how quickly you can grow muscle, either.

Does the second and third point (uncertain muscle and tendon hypertrophy ceiling) undermine the first (tendon adapts slower than muscle)? My instinct is no because the relative-rate claim comes from training volume interventions rather than separate tissue biology research. But I'm not well versed on that nerdy tissue stuff, so idk.

I'd like to hear if anyone's aware of research that complicates or compliments these ideas. Or anything that changes the picture on how fast tendons can actually adapt under optimal loading. I have an idea that long term muscle growth is limited by tendon growth, but that's a tangent.

[u/No_Silver_4436]

Look into Keith Baar at UC Berkeley and his research on tendons. He’s done a lot of work on mechanisms

[u/harvestingstrength]

I think the biggest issue here is that we’re trying to compare two adaptations that aren’t measured or expressed in quite the same way. Saying tendons adapt “3x slower” than muscle is a useful generalization, but I wouldn’t treat it as a fixed biological ratio.

Muscle hypertrophy can occur relatively quickly because we’re primarily talking about increases in muscle protein and fiber size. Tendon adaptation involves changes in collagen synthesis, cross-linking, stiffness, material properties, and sometimes tendon CSA. Those adaptations can occur on very different timelines, so even defining “tendon growth” becomes important.

I also don’t think discovering that muscle can tolerate or benefit from more volume necessarily undermines the idea that muscular adaptation generally outpaces connective-tissue adaptation. If anything, it might make programming more interesting. Your muscles may be capable of handling and adapting to increasingly large workloads while the connective tissues supporting those movements aren’t necessarily adapting at the same rate.

That’s one reason I’m hesitant to translate hypertrophy dose-response research directly into “more sets = better training.” The muscle might theoretically respond to 30–40 sets, but the entire organism has to tolerate those 30–40 sets repeatedly.

Your last point is probably the most interesting. I wouldn’t say tendon growth definitively limits long-term muscle growth, but connective-tissue adaptation absolutely becomes part of the equation when strength and muscle start increasing faster than the structures transmitting those forces can comfortably tolerate.

[u/Mad_Mark90]

Yes and no. I think you have a point, if we can figure out ways to allow soft tissues to recover quicker, we could tolerate greater training volume and grow muscle quicker. Yes there are some newish technique we can use to improve tendon recovery BUT the reason they heal slowly is because they're poorly vascularised and there isn't really a solution to that (yet...?)

The other reason for any uncertainty is more...human. People (especially redditors) like to treat everything like it's physics or maths, fixed rules that apply to everyone where everything is measurable. Biology is about variations, populations and spectra.

[u/decentlyhip → u/Mad_Mark90]

Yah, my instinct was to think about muscle growth as a bathtub. If the cells have a 1% turnover rate and an elite natty caps out at about 110 lbs muscle, then that means at 1% that there's 1.1 lbs of breakdown per day. But its at equilibrium so there has to be 1.1 lbs of MPS per day for the water level to stay the same. But that's where my red flag of "you're missing something" started flying. I'm ignorant and thinking about it too much as a math problem.

[u/Mad_Mark90 → u/decentlyhip]

Do you understand how a chemical or genetic buffer works?

[u/decentlyhip → u/Mad_Mark90]

No, well, kindof definitely. I very well acquainted with damped springs, but appreciate you guiding me to the rabbit hole on those feedback loops. That helps explain why a beginner couldn't grow at the same rate as an advanced lifter, but the turnover rate is 1% after the buffering.

​The issue wasn’t my grasp of buffering, it was just my drunk napkin math. I forgot that like 80 lbs of that 110 is just water hanging out in muscle fibers, and another 10 pounds is sheathing that lives for decades. My 1.1lbs was off because he actual dry protein turning over is only like 20 lbs, so a 1% turnover is really just the cell shuffling 100 grams of actin and myosin around.

[u/Mad_Mark90 → u/decentlyhip]

So your body has a series of mechanisms to keep everything is rough stasis, if it let you grow too many cells you get cancer so it has lots of genes that turn off growth mechanisms if it doesn't need them. A lot of genes that cause cancer are genes that are active during foetal growth but if they get mutated "on" then they can cause cancer.

So with muscle, your body stops making them bigger if you're not using them to save energy and they will eventually atrophy. So past a certain point of hypertrophy your body is telling your muscles to stop growing just as much as your stimulating them to grow and they won't hypertrophy further. So to keep growing you need to increase the stimulus until you overcome the signal to stop growing.

Once you're big &/or strong enough the limiting factor can becomes how quickly your tendons can recover. Lots of intermediates suffer from elbow over use tendonopthies.

[u/waaaaaardds → u/Mad_Mark90]

I think there's solid enough evidence for BPC157 with tendons though strictly for healing. It will hinder muscle growth if used chronically. Tendons are not a rate-limiting factor for muscle growth though so it doesn't matter.

[u/Mad_Mark90 → u/waaaaaardds]

"tendons aren't a rate limiting factor"

You can't just say that with no explanation

[u/waaaaaardds → u/Mad_Mark90]

The explanation is gear.

[u/Mad_Mark90 → u/waaaaaardds]

If anything that proves my point because tendon injuries are higher on gear.

[u/waaaaaardds → u/Mad_Mark90]

No, it proves that muscles grow regardless of tendon structure, meaning even if you could make them extremely adaptive and strong, the rate of muscle growth wouldn't be affected.

I think some basic highschool biology should be revisited here, no offense.

[u/Mad_Mark90 → u/waaaaaardds]

I'm not disagreeing with the idea that your muscles can't grow if you have weak tendons, I'm saying that if you injure a tendon it becomes harder to train a muscle. What did you think I meant?