To Top

Bigger Leaner Results with 4X and X-centric Sets

www.ironmanmagazine.comQ: I started using your 4X Mass Workout a few months ago, and I added negative-accentuated [or X-centric] sets for each muscle at least once a week to help burn fat. I also adjusted my diet slightly, but nothing major. I swear I’m bigger as well as leaner now. Is it an illusion that I’ve put on a lot of muscle because I’m more cut? I weigh about the same, but my abs are much sharper. I always hear that you can’t build muscle while you burn fat. Based on my results, I would have to disagree.

A: There have been studies in which rats gained muscle with weight-bearing exercise while on near-starvation diets. We’re not rats, of course, but I believe it’s possible for humans. I’ve seen it on many occasions.

Using the 4X method in conjunction with some X-centric sets is a very good way to make the bigger-and-leaner results a reality quickly. That’s because you train the force-generating myofibril strands as well as the sarcoplasmic energy fluid, where the fat-burning mitochondria are located.

4X training, as described in the answer to the first question above, is moderate-weight, high-fatigue, growth-threshold training. You repeat it for four sets and go all out on the last. If you get 10 reps, you add a little weight to that exercise at your next workout. 4X works for several reasons:

1) The moderate weight with a rep speed of one second to lift and three to lower over four sets stresses the myofibrils—the slight tears need repair, and your body burns fat making those fixes.

2) The short rests between sets combined with 40 seconds of tension time per set stresses the sarcoplasm, where fat is burned (mitochondria).

3) The short rests also cause lactic acid pooling for muscle burn and growth hormone release—a fat attack and anabolic jack.

With X-centric sets, also called negative-accentuated training, you use a 15RM weight, but you lift in one second and lower in six. The ultraslow negative produces excess trauma in the myofibrils so that your body gets a bigger metabolic uptick outside the gym during the recovery process. In other words, your body burns even more fat as it repairs the myofibrillar microtears caused by the slow negatives. (You get that with 4X, but this style amplifies it.)

Also, seven seconds per rep for eight reps means you get a longer muscle-tension time of almost a minute. That puts more pressure on the sarcoplasmic energy fluid to expand even further, so your muscles get larger and fuller. It’s the short rests between sets in 4X and the longer tension times of X-centric sets that cause the fluid to increase, netting you larger muscles.

The X-centric style also fortifies the fat-burning mitochondria in the sarcoplasm. And, again, the long tension time creates muscle burn, which jacks up fat-burning, hypertrophy-churning growth hormone.

You can see why 4X plus some X-centric sets gives a double dose of fat burning and muscle growth. I suggest that you do the first set of a 4X sequence in X-centric style. Or tack on a fifth, reduced-poundage NA set after your 4X sequence. Take your pick to get big and ripped quick. It works.

Editor’s note: Steve Holman is the author of many bodybuilding best-sellers and the creator of Positions-of-Flexion muscle training. For information on the POF DVD and Size Surge programs, see the ad sections in this issue. Also visit  and for info on X-Rep, 4X and 3D POF methods and e-books.  IM

You must be logged in to post a comment Login

Leave a Reply

More in Latest

  • Whey Makes Everything Grow

      If you have knee pain when you train, you might want to double up on your whey protein shakes. A...

    swarnavaSeptember 30, 2016
  • Cardio For Bigger Muscles

    Many physique athletes stay away from cardio in fear that it will burn up their precious muscle. A new study, published...

    swarnavaSeptember 29, 2016
  • Research: Know Your Roll

      The foam-rolling craze has been a blessing for some, bestowing greater range of motion and less pain on desk-bound athletes...

    swarnavaSeptember 29, 2016
  • Don’t Go Hard When It’s Easy

    Here are two truths about running hills, a tactic long- used by athletes and bodybuilders to lose fat and rapidly improve...

    swarnavaSeptember 29, 2016
  • The Raspberry Is Having A Moment

    Is raspberry the new kale? A tornado of positive research has recently been published about red raspberries. So much, in fact,...

    swarnavaSeptember 28, 2016
  • Shake It Off: Goldenberry Goodness

    Jolt your taste buds and your cells with this novel protein-rich superfood smoothie. By Amanda Burrill, MS   Tangerines, cantaloupe, Greek...

    swarnavaSeptember 26, 2016
  • How To Recover From Anything

    Trip your anabolic ignition switch with the right nutritional choices after a workout By George L. Redmon PhD   All of...

    swarnavaSeptember 23, 2016
  • Fast Food

    These new ready-to-drink options make it easier, cheaper, and tastier than ever to find the protein you need. By Team Iron...

    swarnavaSeptember 22, 2016
  • The Fix Is In

    Self-maintenance is part of the fitness lifestyle. These tools can help you keep your body in tune.   By Amanda Burrill,...

    swarnavaSeptember 12, 2016