Training Is Like Farming

Cluster Training: An Advanced Method to Gain Strength

By Carmen Bott

There are many ways to change the training stimulus of a strength program.  One of the most overlooked variables to manipulate is the rest periods within the sets themselves.  Quite often, athletes and fitness participants will complete a set, rep to rep in a continuous manner.  Depending on the number of reps and the exercise chosen, the set might take 30 seconds to 90 seconds.  Now, there is nothing wrong with this  methodology for certain exercises and for those with specific goals but I want to draw your attention away from this traditional approach to an approach we use at Human Motion to improve strength in our advanced clients. 

The method is called Cluster Training

In this type of training set, a rest interval is prescribed between the reps.  The rest interval can be anywhere from 10 seconds to 30 seconds.  It can be prescribed after a few reps when levels of fatigue are reached, or between each and every rep, almost like the rest a basketball player would take between free throws.  The load can be increased after the rest between each rep then decreased between the reps over a set to capitalize on postactivation potentiation.  Or, perhaps, in the case of a relative strength exercise, the lever arm can be changed during the rest period to alter the biomechanics of the exercise and reduce or increase its intensity between each rep.  There are a few different approaches one can use to employ this method of strength training.  It is up to the skilled practicitioner to decide which approach he/she uses.

The physiology behind cluster training

The goal with cluster training is to improve the QUALITY of the client's performance.  The rest allows the client to produce force at a higher rate and may be beneficial in the development of "power-generating capacity" due to the decrease in repetition-induced fatigue (Haff et al, 2008).  

It is known that Adenosinetriphosphate (ATP) and Creatine Phosphate (CP) are substrates, which provide energy for short-term exercise.  ATP supports muscle contraction and CP is used under anaerobic conditions to rebuild ATP as it is needed and to replenish the body's stores (Brooks et al, 1996).  Creatine Kinase is a catalysing enzyme, which functions rapidly to re-establish the muscle concentration of ATP.  Quantities of ATP and CP in a resting muscle are quite small therefore any utilization must be immediately replaced with an equivalent replenishment.  If the ATP and CP utilization rate exceeds the restoration rate, exercise cannot continue very long.  As CP stores are depleted, the body's ability to quickly replace the spent ATP is seriously impaired.  Fatigue is the result and the inability to produce a maximal muscular contraction.

In an exercising subject, the drop in ATP and CP appear to be related to the relative work intensity (Brooks, 1996).  If the workload is more intense, there is greater the CP depletion, which leads to muscle fatigue (Brooks, 1996).  ATP, however, will maintain its level until CP is greatly reduced.  Thus, it is clear that CP depletion a significant factor leading to muscle fatigue at maximal effort.

Increases in blood lactate levels are also partially responsible for the fatigue-induced performance alterations (Haff, 2008).   During short-term, high intensity exercise, a metabolite called lactate accumulates in the blood as result of lactic acid production exceeding its removal.  The lactic acid dissociates, converting to hydrogen ions, causing a decrease in the pH.  The hydrogen ions accumulate as a result of lactic acid production and can have several negative effects on the exerciser.  Muscle contraction and energy production are adversely affected because of the subsequent decrease in ATP production.  Hydrogen ions also displace calcium in the muscle fibre inferring with the coupling action of the actin-myosin cross-bridges making muscle contraction difficult.

Hypothetically, by incorporating a 20-30 second rest interval BETWEEN repetitions will result in some replenishment of CP, thus diminishing the stimulus for lactic acid and lactate production.

If strength and power gains are at the top of our client's goal list, then cluster training can be a very useful method of training.  In the research, it appears that cluster training has the potential to positively alter the strength training stimulus (Haff, 2008).  It is most effective with pulling exercises like the deadlift, the clean pull, the power clean, the power snatch and variations of these lifts, where the client is most often working above 80% of their 1RM and where quality individual repetition power output is more important than total power output. Isn't our goal as strength coaches to foster a training environment whereby our clients can perform work of high quality? Cluster training also work very well with ballistic-type exercises that have an accelerative profile such as box jumps.

The timely implementation of cluster training into a training program is key.  If a client lacks muscle tone (hypertrophy), has a low work capacity (is deconditioned), lacks adequate hip mobility and trunk stability, then a more traditional approach to their physical development must be taken.  And this might be taken for years!  Cluster training should be used for the more advanced strength client as a means to reach new levels of performance.  However, having said that, clusters work well when subjects are learning new skills (Bott, 2010).  They provide, not only a means of physiological restoration, but a means of mental recovery to allow the newbie to focus on the task and facilitate learning.

For more information on cluster training protocols, email the coaching staff at Human Motion for a program: info@humanmotion.com 

Works cited

Brooks, George, Thomas Fahey and Timothy White.  Exercise Physiology:  Human Bioenergetics and Its Applications.  Mayfield Publishing:  1996.

Haff G.  Cluster Training: A Novel Method for Introducing Training Program Variation. Strength and Conditioning Journal.  Vol 30 N. 1, 2008.

Athlete of the Month: 

Olivia Bevan ~ A Newfound Passion

By: Emily Beers

I've been heavily involved in many different sports, but I've never been even remotely interested in martial arts. That is, until I heard the unmistakable energy in 30-year-old Olivia Bevan's voice when I got her talking about her enthusiastic passion for martial arts. Her energy was so contagious, and suddenly I found myself googling and youtubing something I never thought I would.

"It is so infectious. I just fell in love with it completely," said Bevan, who started her martial arts training at Elements Academy of Martial Arts in Vancouver when she moved to Canada from the UK in March 2008. "I just hit a passion," she said.

She's so passionate about Jiu Jitsu and Muay Thai that she can't stop practicing. "I try to practice on my husband, he won't even let me. He says, 'Nope, back off,'" said Bevan.

So passionate about the sport that Bevan and her training mate, Emma Lynds, are heading to Thailand this March for their first Muay Thai fight. "We decided this in July over a glass of wine at a bar, and now we're down to three months to go. It's getting really intense...and we're getting serious," said Bevan.

Although today Bevan is a serious athlete, it wasn't her original plan to become one. Switching plans, it seems, is something Bevan is good at. When she first moved to Canada with her husband Dylan Bevan, the couple planned to travel the world until they found a place "that really resonated with us," she said. But instead, they got to Vancouver and haven't left yet. "We should be just coming through Russia at this time, but we've settled into Vancouver so well," said Bevan, who is a freelance writer and marketing professional in the city.   

And when she joined her martial arts academy, Bevan didn't intend to get into it competitively. She was simply looking for a fun new sport to get involved with, and to get fit. Fast forward 18 months, and here she is preparing for a fight in Thailand. And like most serious athletes, Bevan has started strength training outside of her sport as well.

Enter Human Motion: for the last few months, Bevan has been training with Cliff Harvey to help her prepare for her fight.

"He is fantastic. Oh my god, he is just so motivating," said Bevan of Harvey. "And I've seen my body literally change. I used to spend time in the gym, but in just a few months with Cliff, I've seen more progress than I did in 15 years at the gym," she said. "I used to go on the treadmill and lift these tiny little weights, but the way he trains me is so much different than that," she said.

This 'different' way of training has helped Bevan tremendously in her sport. "I'm sparring for longer. I'm not getting out of breath. I'm calmer," she said.

Calmer, but Bevan admits she's still nervous about her first fight in Thailand. Nervous, but looking forward to it, she said. And if all goes well, Bevan said she might want to continue and get into MMA fighting. "But I haven't told my mom yet," she said.