The Saturday Meatdive (get it? like, deep-dive? haha!)

“Make sure you get that DEEEEP STRETCH, BRO!”

If you asked someone “why”? They’d say getting a deeper stretch is “better for hypertrophy.” But is it? And should we confidently make this claim right now?

In this article, you’ll learn:

• What does the current data about muscle lengths say?

• The problems with how people are “interpreting” data.

• What the commonly overlooked variables of resistance training are.

• What a reasonable, truly scientific middle ground is here.

The Data

Until recently, we were sure that using more rather than less range of motion on any exercise was better.

Over 20 studies have compared full to partial ranges of various kinds, and, on average, full range of motion training outperformed partial range of motion training (in muscle growth outcomes).

However, this effect was trivial—low in magnitude—and likely insignificant enough to make a large difference in long-term outcomes.

Some data now suggests that training within a longer average muscle length may benefit hypertrophy more than training within a shorter average muscle length.

An example would be comparing two different kinds of curls: one where you only used the bottom half of the curl (longer average muscle length) and the other where you only used the top half (shorter average muscle length).

As is natural with any “trending” topic in the fitness industry, the information disseminated about using longer muscle lengths has become more about making blanket recommendations to other people based on “settled science” and gross extrapolations of it.

So what data do we have, and what can we make of it? Here’s a summary:

• Pedrosa et al. (2021) showed greater quadriceps growth using longer than shorter muscle lengths during leg extensions.

  • Another similar study (McMahon et al. 2014) saw similar results in the lateral quads.

• Maeo et al. (2020) showed greater hypertrophy in the hamstrings when trained at longer compared to shorter lengths.

• Sato et al. (2021) showed greater hypertrophy in the elbow flexors when trained at longer lengths than shorter lengths.

• Maeo et al. (2022) showed that all 3 heads of the triceps grew more with the overhead extension (more lengthened) compared to the “neutral-arm” extension.

  • Stasinaki et al. (2018) showed something different: there were no differences in triceps long-head hypertrophy using lengthened vs. shortened muscle lengths.

• Bloomquist et al. (2013) found that deep squat partials outperformed shallow (top-half) partials in quad strength and size.

The data suggests that longer muscle-length training may be more effective for muscle growth than shorter training. But this isn’t the end of the story.

Problems with Interpretation

As you can see, we currently have a very limited amount of data on this topic. Having fewer than ten studies in favor of a given technique points us in a direction, but it should not allow us to be confident about any definite conclusions.

For example, over 1,000 studies have investigated creatine. That’s a substantial body of evidence capable of supporting very strong claims about it.

Tentative conclusions are the ones that the actual researchers come to (even explicitly in their work). Most authors cite that more data needs to be collected before the public should make statements about this being “settled science.”

Many people will interpret the above studies to mean that long muscle-length training is always better than short muscle-length training.

However, this is a gross extrapolation of the data beyond what the researchers themselves are comfortable creating, and it doesn’t consider several variables that might alter these results in practical application.

And people typically make these conclusions based on SINGLE studies, not multiple studies.

This is a dumb thing to do.

It would be like if you went fishing for the first time, caught a small shark, and concluded that only small sharks exist in the ocean. In reality, many species and ecosystems within the ocean interact with and rely on one another.

Research about muscle building works the same way and we can’t ignore the ocean for a single fish.

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In the rest of this article, you’ll learn:

• What the overlooked variables of hypertrophy outcomes are.

• How stability influences hypertrophy.

  • What soda cans teach you about muscle growth.

• What resistance profiles are and their influence on hypertrophy.

• How novelty impacts results.

• How timelines impact results.

• What a reasonable takeaway from the current data is.

• How to apply this information to your training.

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