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The Size Principle and Speed Sets

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The Size Principle of Muscle Fiber Recruitment tells us that on a standard-tempo set of lifting in one second and lowering in three, the slow-twitch fibers dominate on the earlier, easier reps of a set…

Steve spotting Jonathan on incline dumbbell presses

As those slow-twitch “endurance” fibers crap out, the fast-twitch “power” fibers take over and are stimulated toward the end of a set. It’s why the last hard reps are so important for growth—optimal fast-twitch engagement…

But as neurophysiologist Chad Waterbury notes…

The smallest motor units contract slowest while the largest motor units contract fastest. [But] the actual speed of contraction between a small, slow motor unit and a large, fast one really isn’t the reason you can lift a barbell faster when you recruit the largest motor units…it’s because you’re recruiting ALL of the other motor units.

In other words, with Speed Sets you’re involving more fast-twitch fibers along with the slow-twitch on the early reps. That’s necessary because speed equals more force, which requires fast-twitch fibers…

So with Speed Sets, you get more of a mix throughout the set—more fast-twitch fibers early.

That’s why doing half of your sets in standard style and the other half as Speed Sets, as outlined in Old Man, Young Muscle, will get you growing faster—variation in fiber recruitment, as well as fewer garbage negatives.

You get less muscle damage but more fast-twitch engagement…

I realized the hypertrophic importance of Speed Sets after I dropped them from my workouts as an experiment. More on that, and why I’m wearing a dunce cap, in Saturday’s training newsletter.

Your Efficient Mass-Building Handbook: For more mass-building tips like the above plus complete workouts that include the ideal exercise for each muscle and the best stretch and contracted add-on moves, get your copy of Old Man, Young Muscle.

And you still get The Muscle-On, Belly-Gone “Diet” ebook FREE for a limited time when you add Old Man, Young Muscle to your mass-building library. Go HERE.

New ebook covers - small

Get Old Man, Young Muscle PLUS the Free “Diet” eBook

Till next time, train hard—and smart—for BIG results.

—Steve Holman
Former Editor in Chief, Iron Man Magazine
www.X-Rep.com


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Filed Under: X Files Tagged With: Chad Waterbury, fiber recruitment, size principle, size principle of muscle fiber recruitment, speed sets

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