A: Functional hypertrophy clusters is what you need! This advanced training technique is primarily for building strength but also creates size. It’s based on a technique you may have heard of—rest/pause training.
What are Hypertrophy Cluster Sets?
For hypertrophy cluster sets you use short inter-set rest periods to recruit fast-twitch muscle fibers before the muscle is fatigued. That way you can do more reps than you ordinarily would and also stimulate the type 2, a.k.a. fast-twitch fibers, which usually are not recruited until after the type 1, or slow-twitch, fibers have been fatigued.
As you may know, type 1 muscle fibers are engineered for endurance. They are responsible for a small amount of strength and power; their main task is to get you through the long haul, so they’re slow to fatigue. Type 2 fibers are mainly for strength and power. They give you the burst of explosiveness that you need to get through the task when your type 1 fibers begin to fail.
When you use a standard bodybuilding protocol of eight to 10 reps at a load of 70 to 80 percent of your one-rep max, you recruit only the slow-twitch muscle fibers. It’s not until the type 1s reach fatigue that your brain signals the type 2 fibers to kick in and help. Unfortunately, with the standard training method, you stop lifting when you reach that point of fatigue.
Functional hypertrophy training using cluster sets enables you to recruit type 2 fibers earlier and do more reps than you would with a standard protocol of eight to 12 reps, rest, eight to 12 reps, rest and so on.
Why is that important?
Each muscle fiber has two parts: the sarcoplasm and the sarcomere. When you work only the type 1 fibers, you experience sarcoplasmic hypertrophy, which increases the amount of fluid and noncontractile proteins in the muscle fibers. It doesn’t do much for strength, but it makes you look good because it pumps up the muscles.
On the other hand, when you’re recruiting type 2 muscle fibers, you get sarcomere hypertrophy, which is also called functional hypertrophy because it increases the function of the muscle. It increases the efficiency of neuromuscular signaling as well, making it faster and easier for your brain to recruit the type 2 fibers the next time. Sarcomere hypertrophy increases the contractual proteins in the muscle and the actual number of sarcomeres in the fiber, which means greater strength, greater power and greater size.
The standard protocol of set/rest/set lacks the intensity needed to recruit those type 2 fibers and stimulate functional hypertrophy. To get that intensity, you need to be able to do more reps, which means you have to recruit the type 2 fibers before you’ve fatigued the type 1s. That’s where the inter-set rest periods come in.
How It’s Done
You select your seven-to-eight-rep-max weight, but instead of regular straight sets, you do five cluster sets in the format 4+4+4—with three-minute rest periods between clusters. So, you do four reps, rest 10 seconds, do four more, rest 10 seconds, do four more, and then rest for three minutes—and then you repeat the pattern for five total clusters. If you can complete all three mini-sets with the prescribed reps, increase the weight by 10 percent for the next cluster.
As the loads become more challenging, a typical workout might look like four reps, rest 10 seconds, three reps, rest 10 seconds, two to three reps—and then rest three minutes. As you become stronger, you’ll be able to achieve 4+4+4, which is a total of 12 reps with a load that was previously your seven-to-eight-rep max. Can you say, awesome-sauce? This is sufficient volume and intensity to move you into sarcomere hypertrophy.
Functional hypertrophy clusters are not appropriate for every exercise. They’re best done with barbells so that you can rack the weight during your rest period, and with large, compound movements. They’re also too high an intensity level for long-range work. You do them for a couple of weeks prior to a scheduled deloading phase to keep you from frying your neurological system.
When used correctly and done right, however, hypertrophy cluster sets will not only get you serious results as far as size, but they’ll also improve the efficiency of your neuromuscular communication, making it easier to continue this level of growth every time you use the method.
I do need to stress again that these are not for beginning bodybuilders. They’re for guys who are at an intermediate level, who have been training regularly, with regular progression, for at least a year or two. Get ready for incredible results without having to deal with plateaus.
Editor’s note: Vince Del Monte packed on an amazing 40 pounds of muscle in 24 weeks. He’s known as “the Skinny Guy Savior” and offers a number of courses to help you go from twig to big, including No Nonsense Muscle Building. For more information or to sign up for his free-tips newsletter, visit www.VinceDelMonteFitness.com. IM