Q: I just got your e-book The X-centric Mass Workout. I read it in one sitting—one of your best by far. My question is, you list a number of workouts, but you always have only one X-centric set in them [lift in one second, lower in six], and it’s always the last one in a sequence. Can I do more X-centric sets? What about doing them first instead of last?
A: An X-centric set is a great way to finish off a 4X sequence or to do as your last set of standard sets. That’s because it augments the pump with a longer tension time—about a minute if you get eight reps. It’s also one of the best ways to get muscle innervation.
According to muscle-building authority and IRON MAN scribe Greg Zulak, innervation is “the ability to feel, sense and control the working muscle.” He says getting more innervation is “a shortcut to larger muscle mass and muscular development.”
I agree. Muscle innervation ensures a big pump and heightened fiber recruitment. The slow negative on each rep makes that happen.
So X-centric sets can work well as your first set—or even your first two sets. They will prime fibers to fire on the sets that follow, and that’s especially beneficial for us older trainees looking to prime the pump with a bit of prefatigue so we won’t need mega-heavy weights on the sets that follow.
Here’s how I’ve been doing that on a Progressive-Speed 4X sequence—and it’s working very well on my 55-year-old muscles:
Set 1: X-centric—lift in 1 second and lower in 6—for about 9 reps
Set 2: X-centric—1/6 tempo again—for about 7 reps
Set 3: Standard—lift in 1 second, lower in 3—for 10 to 12 reps
Set 4: X-celeration—final set with speed, each rep lasting 1.5 seconds—for about 12 reps
Can you do the first three sets in X-centric style? Absolutely. There are no rules set in stone. Just be careful, as X-cen sets can get you mighty sore, but they can build mass galore. —Steve Holman
Editor’s note: For more on X-centric sets and moderate-weight growth-threshold 4X mass training, see The 4X Mass Workout 2.0 and The Ultimate Super-Size Crash Course, e-books available at X-Workouts.com. For e-books on X Reps, fat-loss nutrition and bodypart specialization, visit the X-Shop at X-Rep.com.