Q: You’ve mentioned the Growth Threshold a few times. What is that? What does it mean and how do I use it to get bigger?
A: Growth Threshold is a term we borrowed from champion pro bodybuilder Lee Labrada, pictured below. Here’s Lee’s explanation, from our 4X Mass Workout e-book:
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 progressively get more and more tired out, until you reach a point where the muscles 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 the first two sets are fairly easy, you gradually approach the growth threshold. The short 30-to-40-second rests between sets ensure that fatigue accumulates to a size-triggering climax at set 4.
For those not familiar with 4X, you take a weight with which you can get 15 reps, but you only do 10 deliberate reps; rest 30 to 40 seconds, then do 10 more. Rest 30 to 40 seconds again, then do 10 more. Rest 30 to 40 seconds one last time, then go to failure. If you get 10 on that fourth set, add weight to that exercise at your next workout…
As Labrada says,
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.
And 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 will give you size increases in both the myofibrils, the actin-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 3-way Positions-of-Flexion programs for each muscle—midrange, stretch, and contracted, you reach the growth threshold for each and get a triple dose of muscle growth.
NOTE: If you’ve been training with standard myofibrillar-dominant heavy sets—tension times of 20 seconds and rests of 2 minutes or more—you may want to increase your sarcoplasmic mass with a few weeks of PURE density training. For that, give 10×10 training a spin. You take a weight with which you can get 20 reps, but you only do 10. Rest 30 seconds, then 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.
Till next time, train hard—and smart—for BIG results.
—Steve Holman and Jonathan Lawson
Build MASS with bodyweight training
One way you’re guaranteed to pack on stacks of muscle is through a process called muscle protein synthesis (MPS), which more than doubles 24 hours after an intense workout…
Until recently, MPS was only elevated when trainees would lift 70-90% of their one-rep max…
That’s not only dangerous for your joints, but it also sets you up for high injury risk every time you exercise…
It used to be believed that training with your own bodyweight couldn’t get you the same results as training with your 70-90% one rep max… Until NOW.