by Steve Holman and Jonathan Lawson Iron Man Magazine
So many people believe that getting stronger with lower-rep, pure anaerobic work is the key to getting bigger. It does get you somewhat bigger but primarily in the myofibrils, which are the actin-and-myosin pairings inside the muscle fibers that produce force. That, however, is only half of the fibers’ growth potential.
The other big hypertrophy producer—and the one many scientists believe is the dominant one, as you’ll see in a moment—is the sarcoplasm, the energy fluid in the muscle fiber that contains glycogen, mitochondria and ATP. That’s why the biggest bodybuilders are 2A fiber–dominant—that is, they have fibers with both power and endurance components.
Longer tension times cause sarcoplasmic expansion; heavy weights and low reps cause more myofibrillar growth. You need both for ultimate muscle size, but your goals will determine which one you focus on. Here’s what researchers Vladimir Zatsiorsky, Ph.D., and William Kraemer, Ph.D., wrote in Science and Practice of Strength Training:
“Mostly myofibrillar [actin-and-myosin pairings] hypertrophy is found in elite weightlifters, whereas sarcoplasmic [endurance fluid] hypertrophy is typically seen in bodybuilders.”
That’s why many scientists are now saying that sarcoplasmic expansion is the biggest key to muscle size—and why short rests between sets, as with the 4X method, and/or longer tension times are so important for building extreme muscle size.
It makes sense considering the research demonstrating that the biggest bodybuilders have mostly dual-component 2A fast-twitch fibers and that their size is sarcoplasmic dominant—as many top bodybuilders have discovered.
For example, IFBB pro Johnnie Jackson, who also competes in powerlifting, has said that when he trains ultraheavy with low reps exclusively, he gets smaller, not bigger. That’s due to lack of tension time. He must switch to using more reps and/or short rests between sets to hit the stage at his biggest and freakiest.
The best size gains happen the fastest with optimal stimulation of both the myofibrils and the sarcoplasm. There are a number of ways to make that happen:
• Use full-range Positions of Flexion—midrange, stretch and contracted exercises for each bodypart, with power on the big, midrange move and higher reps and/or drop sets on the last exercise, a continuous-tension contracted-position move like leg extensions, concentration curls, lateral raises and pushdowns.
• Add X-centric sets. Use a one-second positive and a six-second negative on every rep, and go to failure, which should come at about around rep seven. That provides almost 50 seconds of tension time for sarcoplasmic expansion, plus the negative emphasis stresses the myofibrils. We suggest adding only one or two negative-accentuated sets per body-part because they’re taxing and will make you sore.
• Use pure 4X training, a balance of myofibrillar and sarcoplasmic stress. You take a weight with which you can get 15 reps, but you do only 10; rest 30 seconds, and then do 10 more—and so on for four sets. You go all out on the fourth set, and if you get 10 reps, you add weight to that exercise at your next workout.
You can use more combo-to-grow methods and tactics, such as drop sets, supersets and DC training. The bottom line is that for the fastest gains possible in ultimate muscle size, you need both fast-twitch power and endurance work to build both “sides” of the key 2A fibers for a double dose of growth. Otherwise you’ll grow slowly rather than faster than ever.
—Steve Holman and Jonathan Lawson
Editor’s note: For more on achieving extreme hypertrophy, see Secrets to Ultimate Muscle Growth, a free e-book available at www.X-Rep.com.