Q: You’ve mentioned the “growth threshold” a few times in your e-zine and Train, Eat, Grow. What does it mean, and how do I use it to get bigger?
A: “Growth threshold” is a term I borrowed from champion pro bodybuilder Lee Labrada. Here’s Lee’s explanation, which Jonathan Lawson and I used in our e-book 4X Mass Workout:
“The growth threshold is the point at which the level of fatigue in the muscle is high enough that a growth response is elicited. Your goal during a workout should be to fatigue the target muscles you are training more and more with each succeeding set. In other words, you want the muscles to get progressively more tired out until you reach a point where they are functionally ‘worn out.’ Signals are sent to the brain that set up the compensation, or growth, process during the postworkout period so that in future workouts you can handle it.”
Because you use the same weight on every set of a 4X sequence and because the first two sets are fairly easy, you gradually approach the growth threshold. The short 30-to-40-second rests between sets insure that fatigue accumulates to a size-triggering climax at set four.
For those not familiar with 4X, you take a weight with which you can get 15 reps, but you do only 10 deliberate reps; rest 30 to 40 seconds, and then do 10 more. Rest 30 to 40 seconds again, and do 10 more. Rest 30 to 40 seconds one last time, and then go to failure. If you get 10 on that fourth set, add weight to that exercise at your next workout.
As Labrada explains, “I do not let my muscles regain all of their strength before starting the next set. After all, my goal is to fatigue my muscles more and more with each succeeding set until they hit the growth threshold.”
That’s what 4X sequences are all about—reaching the critical growth threshold without overtaxing the body’s recovery systems so you continue to ignite new, dramatic muscle growth at every workout. 4X training gives you size increases in both the myofibrils, the actin and myosin strands that produce force, and the sarcoplasmic endurance fluid in the muscle fibers.
And if you use a 4X sequence on the full-range three-way Positions-of-Flexion programs for each muscle—midrange, stretch and contracted—you reach the growth threshold on each and get a triple dose of muscle growth.
Incidentally, if you’ve been training with standard myofibrillar-dominant heavy sets—tension times of 20 seconds and rests between sets of two minutes or more—you may want to up your sarcoplasmic mass with a few weeks of pure density training. I suggest you give 10×10 a spin. You take a weight with which you can get 20 reps, but you do only 10. Rest 30 seconds, and do 10 more—and so on until you complete 10 sets. The last few rounds will be brutal, but the pump and sarcoplasmic size you ignite will be unreal. Use it on only one exercise per bodypart—10 minutes for each—for two weeks and watch the amazing changes in your physique.
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, visit www.Home-Gym.com. Also visit www.X-Rep.com and X-Workouts.com for info on X-Rep, 4X and 3D POF methods and e-books.