Coaching, jumps, sprints & more
Everything about jumping and sprinting and how to improve your performance
LET'S TALK & TRY TO UNDERSTAND MORE ABOUT THE CENTRAL NERVOUS SYSTEM AS IT RELATES TO SPORTS PERFORMANCE
IN my latest Coach-Athlete members video on my YouTube channel on Fast Twitch Muscle Fibre I mention the CNS ... I thought it might therefore be an idea to provide a little more detail to help understanding and learning. The following is a little theoretical but understanding in overview at least of what the CNS is and out it can effect sports performance is usual. I may follow up on this post in a video or in further posts.
The central nervous system receives, interprets and relays signals from around the body, via the spinal cord and brain. It is a complex system. Perhaps it is because of this that it receives less attention as a constituent of sports training. Yet this mechanism is involved in every aspect of sports performance. Understanding its role and utilising it to its fullest extent is crucial in order to maximise training adaption.
What is the CNS?
The CNS consists of the brain and spinal cord as indicated. It’s a control system for the body (the other part of the nervous system is the peripheral nervous system - PNS which is outside the brain and spinal cord). The brain is highly complex - in terms of sports performance the cerebellum and diencephalon are important CNS constituents. Understanding their role indicates just how integral the CNS is to sports performance. The cerebellum is the second largest part of the brain. It is involved in co-ordinating muscles to allow precise movements and the control of balance and posture The diencephalon contains two important structures called the thalamus and the hypothalamus. The former acts as a relay station for incoming sensory nerve impulses, sending them onto relevant areas of the brain for processing. It is responsible for letting your brain know what's happening outside of your body. The hypothalamus plays a vital role in keeping conditions inside your body constant. It does this by regulating your body temperature, thirst and hunger, for example – and by controlling the release of hormones from the nearby pituitary gland. Receptor and effector organs Receptor organs include the ears, eyes and crucially in the context of this article muscles. These - as their name suggests - collect information, which is then relayed via the CNS. The CNS then interprets this information and sends it back to ‘effector’ organs - which carry out the body’s response to the stimuli – so with reference to the topic of this article, for example, a muscle action.
There is debate as to the extent of the automatic (unconscious) and interpreted (conscious) response of the CNS as it affects sports performance. Some actions will largely be automatic, for example, the stretch/reflex involved in the leg muscles when jumping; whilst others will be more specifically interpreted by the brain - such as the fatigue signals it receives at the end of a marathon. This is where, for the latter, will-power may become an influencing factor to cajole the body into continuing. It is the degree of conscious interpretation that will vary. Fatigue and the CNS Fatigue during training sessions/competition - or as a result of training programmes that do not account for the restoration of CNS energy - can have detrimental effects on sports performance, whether interpreted consciously or unconsciously. (This is what I often refer to in my videos when talking about workouts affects on the CNS.)
Sensory input can result in the CNS eliciting ‘programmed’ sports skill responses – this can be positive and negative Having provided a brief introduction to the functioning of the CNS we now move onto how it affects sports performance in more detail, firstly in terms of the interpretation and reaction to repeated training and sports skill learning.
Research indicates that prolonged sports involvement influences the way the CNS ‘controls’ muscular recruitment and patterning - ‘interpreting’ signals, under certain circumstances is automatic as noted. Researchers from Finland investigated the influence of sports background on leg muscle co-ordination during concentric and drop vertical jumps. Five different athlete groups were chosen as subjects: track and field jumpers, swimmers, and footballers and poor and good vertical jumpers. ‘Motor versatility’ was used as the research focus - i.e. the ability of an athlete from one sport to ‘transfer’ skill to another. The team wanted to find out about different movement models (i.e. how the sports performers recruited their muscles) and the role of the CNS:
Not surprisingly it was discovered that the jumpers performed the most powerful vertical jumps. Their legs had greater muscular stiffness compared to the swimmers - who turned out to be the poorest jumpers (their leg muscles were more attuned to kicking). Specifically, in terms of the subject matter of this post, it was discovered that the CNS influenced differently the firing and recruitment patterns of the sports participants’ muscles involved. For example: The agonist and antagonist muscles of the swimmers of both the thigh and shank showed co-contraction instead of reciprocal innervation – which was displayed by the jumpers. Basically, the swimmers were unable to create the stretch/reflex action in their leg muscles as powerfully as the jumpers’ muscles - which resulted in poorer jump performance. The football players showed an intermediate level of innervation. Basically, their muscles were able to use the stretch/reflex mechanism better than the swimmers to generate jumping power. However, their ability was mitigated by a tendency to produce a new burst of activity at the end of the contact phase. Basically, unlike the jumpers whose legs fired dynamically and rapidly to produce jumping power, the footballers jumping movement was more contrived. Rather than one ‘explosion’ into the jump, there was a more staccato muscular firing rhythm.
The researchers attributed these differences to the specifics of the individuals’ sports and crucially years of relevant training and the effects that these had on the CNS. Specifically they stated, “The results suggest that prolonged training in a specific sport will cause the central nervous system to program muscle coordination according to the demands of that sport.” Adding, “That (the) learned skill-reflex ….. of the CNS seems to interfere hierarchically in the performance program of another task.”
This is positive if you train correctly for your sport and maximise the CNS and its great potential to elicit your sports desired training effect. However, this is not so good if you change sports (and have to adopt a new movement pattern that might be compromised by your prior sport’s involvement) or if you train in a way that compromises the CNS’s contribution to your sport.
Electromyogr Clin Neurophysiol. 2003 Apr-May;43(3):141-56.