all posts post new thread

Kettlebell Infographic: Short Rest Periods = Less Hypertrophy

Status
Closed Thread. (Continue Discussion of This Topic by Starting a New Thread.)
So what is optimal? I've read and heard 60-90 seconds.
 
Experiment on yourself. In the past I've had good results by waiting a bit longer between sets. What I found was that I could use a heavier weight by resting say 3 to 5 minutes between sets.
 
I hear the term "CNS fatigue" thrown around a lot, but can anyone tell me what it is that fatigues in the CNS? Honestly curious. I could think about maybe neurotransmitter depletion, but then, I can play chess for hours on ends before I get tired. How does a few seconds of exerting muscles lead to depletion while seconds of chess don't? I never found a good explanation online (not that I spent days researching this, but still, I looked around a bit).
 
Manuel Fortin said:
I hear the term "CNS fatigue" thrown around a lot, but can anyone tell me what it is that fatigues in the CNS? Honestly curious. I could think about maybe neurotransmitter depletion, but then, I can play chess for hours on ends before I get tired. How does a few seconds of exerting muscles lead to depletion while seconds of chess don't? I never found a good explanation online (not that I spent days researching this, but still, I looked around a bit).
Click to expand...

I have no explanation that's scientific in nature because I have no idea. I can however relate this: when I have trained at programs in the past wherein my heart rate soars, my limbs are left shaky and I'm totally breathless, I have to be very strict at allowing ample recovery. If I don't allow for recovery, I wake up unrefreshed and dread going to my garage for a training session rather than looking forward to it and I actually get weaker! I am assuming what I have described is caused by too much "higher intensity" work and not enough recovery and the combination can fry the CNS??
 
Central nervous system fatigue - Wikipedia "Central nervous system fatigue, or central fatigue, is a form of fatigue that is associated with changes in the synaptic concentration of neurotransmitters within the central nervous system (CNS; including the brain and spinal cord) which affects exercise performance and muscle function and cannot be explained by peripheral factors that affect muscle function. In healthy individuals, central fatigue can occur from prolonged exercise and is associated with neurochemical changes in the brain, primarily involving serotonin (5-HT), noradrenaline, and dopamine. Central fatigue plays an important role in endurance sports and also highlights the importance of proper nutrition in endurance athletes."

That's about what I understand about it.

There are 3 specific situations where I personally feel what I would call CNS fatigue:
  1. After a long endurance event like a 100 mile bike ride (or 62 mile bike ride, if I haven't been riding a lot)
  2. After a heavy deadlift session
  3. After a really intense tension-generating session such as the 1-day bodyweight course. Tension galore. I definitely felt fried in a new way after that.
All of these bring on a deep fatigue feeling that is more than muscular or peripheral fatigue. The brain still works fine, and the muscles still work fine, but the brain's will to move the body just seems... dulled.
 
Manuel Fortin said:
I hear the term "CNS fatigue" thrown around a lot, but can anyone tell me what it is that fatigues in the CNS? Honestly curious. I could think about maybe neurotransmitter depletion, but then, I can play chess for hours on ends before I get tired. How does a few seconds of exerting muscles lead to depletion while seconds of chess don't? I never found a good explanation online (not that I spent days researching this, but still, I looked around a bit).
Click to expand...


As far as the science goes, I don't think there is a lot of hard facts to go by.

Anecdotally, it takes high tension, effort, time under load.

I suspect it has something to do with sustained higher firing rates or total number of high tetanic requests of a muscle in a short period of time regardless of ATP metabolism.

I always feel physically refreshed fairly quickly after doing Isometrics, but mentally I have no desire to jump right in and do another session anytime soon.

Relative to the chart, I'd suspect the physical fatigue has more to do with short rest periods than CNS burnout, which seems to be cumulative over a longer period. I know Thib recommends longer rest periods to begin but with a very slow reduction over time based on what the individual can absorb - this being metabolic fatigue.

Edit:
moreover, the graphic shows an impossible reduction of motor unit recruitment, far more than one would experience with most tradition hypertrophy sessions. The unanswered question is whether the reduced number of motor units being activated are ones that didn't kick in earlier and so are all that's left. Or if it even matters as you want to fatigue ALL the motor units not just the high threshold ones.
Relative to hypertrophy, not power.
 
Last edited:
@AnnaC I only browsed the Wikipedia link. I will read it in greater details later. However, it seems to talk about endurance sports and long sessions, not doing a few sets of deadlifts. Why do people talk about "frying your CNS" when doing a few heavy deadlifts too often. This seems a bit like "bro science" to me. There is an effect when training too hard. If you lift too heavy too often, your brain will be foggy. However, I am not convinced that this is because you somehow exhausted your neurotransmitters. I read a lot about fatigue and will try to post a more coherent post later. Now, my wife is waiting for me for dinner ;)
 
I am not seeing any actual evidence that short rest is not good for hypertrophy, or any reference to such evidence. The post states "Strength training with short rests is known to produce less muscle growth than similar training with longer rest periods. This is likely because..."

"Is known to...?" "likely because...?" This just seems like circular reasoning and speculation. I'm not seeing any there there.

The graphic also does not define "short" or "long" and the graphs are not labeled with any kind of units or measurements.

Maybe this is based on more than nothing but, as presented, it strikes me as essentially information-free.
 
There is the argument that fatigue is fatigue.There are many aspects that haven't been differentiated and the mechanisms, as a whole or in part, are not full understood.
A proposal, theory which perhaps shifts to cns fatigue for 1Rms, or near max loading, sprinters etc is the role of creatine.
Creatine is often talked about in its role of muscle atp, it also has a role in the cns and neural atp supply.
A creatine drain results in impaired neural function, a possible reason for dullness, lack of readiness etc.
Of course, it isn't just that but something to think about.....
It's a strange thing because whilst there are many factors to fatigue with some arguing cns fatigue shouldn't be seen in isolation, from my experiences there is some sort of difference. Maybe those differences are heightened because of some other variable or input...lack of sleep or broken sleep due to excessive excitation , a global stress response etc.
 
watchnerd said:
This seems to agree with Easy Strength and other Strongfirst approaches:

View attachment 7972

Infographic from Chris Beardsley at Strength & Conditioning research:

Chris Beardsley on Instagram: “Contrary to the practices of many bodybuilders, using short rest periods may not be very effective for hypertrophy, likely due to the…”
Click to expand...

Chris Beardsley's Research

Chris is one of my favorites. I get his email information.

Dr Brad Schoenfeld's research supports Beardsley's; longer rest periods for hypertrophy.

However, one of the primary factors for hypertrophy, based on Shoenfeld's research is...

Metabolic Stress

This is what is commonly termed as, The Pump.

The Pump is created when arterial blood flow from the heart is pumped into the working muscles.

The muscle contraction in performing repetition in a set restricts ventricle blood flow back to the heart. The blood is trapped in the muscles being worked, pumping them up.

The Pump increases the production of lactate which trigger hypertrophy. Lactate accumulation is one a prime factors behind...

KAATSU/Occlusion Training
Practical Occlusion Training
Dr Jeremy Loenneke

Here is the downstream, domino effect...

"Lactic Acid > Acidic Environment > Growth Hormone Secretion"

The Reason for Short Rest Periods Between Hypertrophy Sets

1) With short rest periods between sets (about 60 seconds) there is less ventricle blood flows back to the heart.

2) With short rest period, The Pump is magnified; more blood remain in the muscles, less escapes.

3) The Pump is magnified to an even greater extent when a tourniquet is applied to your leg or arm with moderate tension; allowing a trickle of ventricle blood flow back to the heart.

Longer Rest Periods Between Hypertrophy Sets

Longer rest period between sets allow for more deflation of The Pump and less lactate accumulation.

Long rest periods work for increasing muscle mass; more effective at increasing strength compared to short rest periods.

However, based on research and anecdotal data, short rest period work, as well.

Summary

Long Rest Periods and Short Rest Periods elicit a somewhat different Hypertrophy Training Effect. Each has a benefit.

Kenny Croxdale
 
Last edited:
kennycro@@aol.com said:
Long Rest Periods and Short Rest Periods elicit a somewhat different Hypertrophy Training Effect. Each has a benefit.
Click to expand...
When I was a muscle junky in the 80's I would work the muscle to the greatest pump I could achieve using the heaviest loads I could manage to get there. Pumping for the sake of pumping using light weights works for some people I guess, but it never did for me.
Heavy bench press and squats were the big mass builders I used most, but those required more rest between sets.
Training arms (my favorite)I loved to superset heavy close grip bench with heavy barbell curls for instance as a mass builder, but again too much weight didn't work and too little weight didn't work.. you have to find what works for you.

There is a balancing act for rest period, load and quality of the pump. Heavier loads lead to greater muscle mass for me, so I used a 10 rep format with as much weight as I could handle with strict form. Some guys swore by 8 reps and so on.. it's very individual as to what works.

Building mass and strength is tough to balance.
 
kennycro@@aol.com said:
Longer rest period between sets allow for more deflation of The Pump and less lactate accumulation.
Click to expand...
Is this where more sets equals better for the desired effect and why programs like German Volume Training (GVT) are used?
 
Bro Mo said:
Is this where more sets equals better for the desired effect and why programs like German Volume Training (GVT) are used?
Click to expand...

German Voluming Training

Charles Poliquin, who passed away recently, was a big proponent of German Volume Training.

Poliuquin was a brilliant Strength Coach. One of the first to promote Undulating Periodization Training as a means of evoking a greater training effect in the National Strength and Condition Journal in 1989.

As you probably know, German Volume Training revolved around performing one exercise for 10 sets of 10 repetitions, with rest period between sets of 60 seconds for upper body and 90 seconds for lower the lower body prescribed by Poliquin.

Growth Hormone Synergism

This training method parallels German Volume Training. It was based on Dr Doug Crist's (formerly an Olympic Lifter) hypertrophy research that was published around 1992.

The Program

It revolved around Super Sets of opposing muscle groups preformed back to back with a 60 second rest period after each Super Set. As an example, Bent Over Rows followed immediately with a Bench Press.

Crist research found this method dramatically increased growth hormone production.

German Volume Training and KAATSU/Occlusion Training essentially use the same underlying protocol of increasing Lactate, which produces an anabolic hormonal cascade...

"Lactic Acid > Acidic Environment > Growth Hormone Secretion"
Practical Occlusion Training
Dr Jeremy Loenneke

Bro Mo said:
...more sets equals better for the desired effect...
Click to expand...

Volume For Hypertrophy

Yes, research and anecdotal data have demonstrated that performing more sets (Volume) of an exercise is one of the key components of hypertrophy.

Kenny Croxdale
 
Status
Closed Thread. (Continue Discussion of This Topic by Starting a New Thread.)
Back
Top Bottom