CNS Fatigue and Sprinting

CNS Fatigue and Sprinting

 Coach Ange’s remarks:

The following content has been taken from “The Charlie Francis Training System”. By Charlie Francis (questions by Paul Patterson). Copyright Angela Coon 2018

In the past 8 years people looking to do graduate work on CNS fatigue have contacted me and it’s role in sprinting. They had been looking to Coach Francis as a pioneer in this area as it pertained to his extensive experience as athlete and coach with Olympic level sprinting. ( Note: Coach Charlie Francis is not the only coach with experience in CNS fatigue. He is one of few to write and discuss his ideas and work).

According to what I learned from Francis it takes several years to properly develop the nervous system of an athlete.  Each person has a unique CNS.  One athlete may develop a strong and resilient CNS while another performing similar work may not respond the same way.  Some athletes may not be able to handle high intensity work more than 2 x per week. As an athlete I spent all day pursuing the hope to apply 3 high intensity sessions a week. Mostly I was successful accomplishing this but sometimes it did not happen and you need to accept this for the greater good of your overall training program.  Athletes with superior natural work capacities may appear to defy some of the rules of load progression and super- compensation thereby tempting coaches to ignore the existence of CNS fatigue. My experiences learning about CNS tolerance have developed over time based on my life as an elite athlete and my experiences in my business working with all ages and levels of athletes.  I have learned that by following sound training methodology and practicing routine regeneration you will have your greatest ability to apply the highest intensity with greatest frequency. Be prepared to adjust rules about volume guidelines if as a coach you see technical aspects of training degrade. Sprinting can be one of the best ways to exercise and strengthen Central Nervous System.

Excerpt from "The Charlie Francis Training System"  

Central Nervous System Fatigue goes hand in hand with sprinting.  Due to the extremely high rate of motor neuron firing at top running speeds it is of paramount importance that the Central Nervous System CNS performs optimally. Optimal functioning of CNS requires the following characteristics.

  1. CNS has to be fully regenerated so that the chemical environment required for optimal transmission of nervous signals is intact.
  2. Motor pathways, characteristic of optimal technique of motor and efficient routing of motor signals must be in place

It is necessary to understand the difference between CNS fatigue and peripheral muscular fatigue. CNS fatigues is reached when the by products of high intensity exercise build up to the point where the CNS impulses necessary to voluntarily contract muscle fiber are handicapped. Total muscle fatigue is typified by the inability to contract the muscle even if externally stimulated by EMS.

Appropriate training creates chemical changes, which advance the capacity to do both CNS work and muscular endurance under conditions of correct technique, before fatigue is reached.

CNS fatigue vs Muscular Fatigue

Central Nervous System (CNS) overtraining is caused by high intensity work occurring (i)too frequently in the training cycle (ii)in too high a volume in a single training session or (iii)by the attempt to introduce  high intensity work too rapidly in the program when residual fatigue still exists (i.e. incomplete regeneration)

Symptoms of CNS Fatigue

Symptoms of CNS fatigue include loss of performance or technique (with onset of fatigue in sprinting the foot stays on the ground perceptibly longer during the support phase), frequent cramps, involuntary trembling or shaking of the muscles after a workout, flickering eyelids, loss of concentration, sleeplessness, and general malaise.

Some examples of high stress CNS focused work are the following:

 *Sprints at maximum speed or 100% intensity (30, 60meter, 80 to 100m)

* Heavy weights allowing only a few repetitions (i.e.2 to 5 repetitions)


*Stair running

*Explosive jumping, hopping, skipping, bounding routines (plyometrics)

*Medicine ball work


QUESTION = What is your functional definition of CNS related work?

 CNS work and power work are synonymous. Anytime the athlete is focusing on maximum speed and explosion or explosiveness the CNS is being taxed.

Properly executed ( intense) medicine ball work, starts, acceleration work, and weight work using heavy loads all represent different types of CNS work.

The precision and monitoring of CNS work must be very precise. For any workout you have a certain volume of CNS related work in mind but you adjust this volume

in accordance the apparent energy status of the athletes on arriving at the workout as it is revealed during the warm up and as it changes during the actual performance of CNS related work. You stop when a personal best (PB) or near PB is performed or when intensity or technique visibly degrades.

Coach Ange’s comments:

I had been advising a family of an athlete whom I coached and have continued to coach on and off over the past several years. I visiting this athlete at the school I recommended he attend because of prestige of the school not because of the coaching or athletic performance of the school.  I attended practice once and noticed the coaches failed to watch any part of the warm up. Apparently this was the norm.  The first point of success for coaches and athletes in each training session begins with the warm up. The coach must watch every aspect of the athletes training before solidifying work of a session.  It is at this point of the training that first signs of CNS fatigue may be detected.

Injuries will be prevented with information gathered from watching the warm-up. I was taught to not take my eyes off the athletes from beginning to end of the training session.

Excerpt from The Charlie Francis Training System

What can be done to improve the CNS output?

We feel that we can get up o 40% more CNS power training time related to the performance of high intensity training by incorporating properly executed massage and regeneration.

Coach Ange’s Final Comments on Sprinting and the Central Nervous System

It’s my opinion that one of the most difficult aspects of training or coaching is to teach judgment of how much training to do and at what intensity. One of the most common mistakes made in training is the idea that performing more work is better because a person is capable of performing the work.  LESS IS USUALLY MORE. The trick is to find the balance between work and rest. 

You may wish to take a look at a science perspective of CNS fatigue in speed and power sports here.


"Sprint your own race”






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