Q: After reading one of your articles that discussed the study where light, longer sets built muscle, I was thinking that maybe that’s why X Reps build so much size. Because they’re partial reps where the muscle is stretched, you block blood flow and get more tension time by making the set last longer. Do you think that’s the case—that X Reps work because they make a set last longer?
A: No doubt that ex-tending the set with X-Reps is one reason those power partials are so effective at building more muscle. As you said, you not only pulse at the
For those who missed the article being referred to, the study basically showed that
Why did the longer, lighter sets work so well? Occlusion, or blood-flow blockage, as the quads did sustained work for an extended time caused an anabolic cascade: growth hormone surge, more fast-twitch fiber recruitment due to oxygen debt (no blood flow, which is where slow-twitch fibers get oxygen), capillary bed expansion (which can lead to more vascularity, by the way) and mitochondria development (the powerhouse of the cell where fat is burned).
Extending a set with X-Rep partials may cause some or all of those things to happen as well—but because X-Reps are at the end of a set to exhaustion at the target muscles’ strongest point on the stroke, you also get more high-growth fast-twitch fibers to fire (for more on that, see the size principle of fiber recruitment, analyzed in many of our e-books).
So while you do get occlusion and extended tension time with end-of-set X Reps, we consider the technique more of a fast-twitch fiber activator. For example, at the end of a set of incline presses, when you can’t get any more full-range reps, you lower the bar to a few inches off your chest and drive up eight inches, lower and repeat, firing out as many low-end partials as you can.
Those short eight-inch reps at the point where the upper chest is elongated and still able to fire brings in more high-threshold motor units that activate the fast-twitch fibers with the most growth. The occlusion and extra tension are bonuses that also boost fast-twitch recruitment.
You get the best occlusive effects with isolation exercises that have continuous tension, what we call contracted-position exercises in 3D Positions of Flexion (leg extensions, triceps pushdowns, etc). Those are best used to finish off the muscle—do them last in your bodypart routines.
[Note: For more on X Reps, see the original X-Rep manual, The Ultimate Mass Workout e-book; for contracted-position exercises for every bodypart, see the POF 3D Muscle Matrix on pages 50-51 in the 3D Muscle Building e-book, which also contains Jonathan’s 20-pounds-of-muscle-in-10-weeks program.]
Till next time, train hard—and smart—for BIG results.
—Steve Holman and Jonathan Lawson
Testosterone prescriptions do more HARM than good for older men
Millions of men are struggling with the problems associated with low-T in today’s world, such as extra belly and chest fat, low energy and stamina, lack of sexual desire, ED problems, and loss of muscle.
Sadly, millions of men also turn to Testosterone Replacement Therapy (TRT) to try to overcome these problems and try to feel like a new man again…BUT there are some VERY concerning problems with TRT that every man NEEDS to know.
After reading the article below, you might want to consider alternate routes of boosting your T levels naturally instead of through something that’s potentially as harmful as TRT…
–> Why Testosterone Replacement Therapy can do more HARM than good (for any ladies reading this, please pass this on to your husband or boyfriend if they are using or have considered using TRT)