Tag Archives: Central nervous system

Sleep and Competition

This post comes in response to a question we received from a reader. “Why is getting a good night sleep important before competition?”

Sleep is restorative and not preparatory in terms of physiological function. When we sleep there is a down regulation of the Sympathetic Nervous System (SNS). This is our “Fight mode” which reacts to stress and allows us to “Perform”. The opposite is the Parasympathetic Nervous System (PNS). This is our “Rest Mode”. It allows the organs to dial back on activity and gives them a chance to recover fully. When in rest mode the immune system is highly active. Time and energy goes into repairing damaged tissues and resupplying fuel stores. If we were constantly in fight mode the body would eventually break down and the safety stops would be activated. Our immune system would also become depressed and we would become more susceptible to infections and illness.

Studies examining the physiological response to impaired or reduced sleep prior to competition have shown no significant negative impact. It does not have a direct impact on physiological capacity or function. However, mental and cognitive function are significantly reduced. This on its own will cause noticeable decrements in performance. In terms of an athletes mood state there will be a drastic decline in motivation depending on the individual. Their ability to push themselves mentally and stay alert will be reduced.It is also important to note that we are discussing lack of sleep rather than a night on the town. The later has many other factors added to the mix which can cause issues.

When an an athlete may be competing or training for multiple consecutive days, sleep plays a restorative role. It becomes a major part of the bodies natural recovery system. Disturbed or impaired sleep my hinder the restorative processes that have been mentioned from taking place. The ability of an athlete to recover is vital in maintaining performance when there are multiple days of activity.

From a practical perspective, an athlete should always try to get adequate sleep. The optimal amount will vary from one individual to another. If an athlete misses sleep before the competition has started they should place their focus on mental preparation and motivation as this will be the site for concern. After the race they should look to get sleep for both mental and physiological benefits. Inadequate sleep will result in poor recovery which will likely result in a drop in performance on consecutive competition days.

Athletes should make note of what is normal for them and what lets them perform at their best. Having a record of sleep is a good tool to allow an athlete identify when there might be an issue. This can be useful in the grand scheme as certain trends in sleep patterns can be identified and managed. Many athletes suffer from sleep disturbances as a result of nutrition, travel, stress and a wide range of factors which can be managed.

In conclusion, a lack of sleep before a big competition is not ideal preparation for an athlete. It is not always avoidable and so it is important for them to understand how it might effect them. It is a factor which should be monitored and managed as part of an athletes routine.

Science of strength!

In this post I will discuss the physiological components that make up physical strength. In general the strength of a muscle is determined by its cross sectional mass. When we assess the improvement of strength in a muscular contraction, we see a significant increase in force output in a short space of time with no change in mass. This shows us that there is also a neural component that plays a significant role in strength. In order for a muscle fiber to hit a peak contraction it must be stimulated fully. A beginner to strength training will be unable to reach his true max because he will be neurally untrained. This means he is not capable of using all his muscle fibers or even capable of using the select few to their full potential.

When we want to move, we send a chemo-electrical signal from brain to the muscle which results in a contraction. The more signals we send the more forceful the contraction. In order to achieve maximum contraction we must have a constant and rapid train of impulses coming from our brain. The route the impulse takes down the nerves must be capable of sustaining and transmitting these signals. Early in our training it is these nerves which improve at delivering stimulus, that results in strength improvements.

There are several factors which can prevent us achieving maximum contractile forces. We have safety mechanisms which prevent us reaching our limits in order to prevent damage to our muscle tissue. These mechanisms are largely involuntary and are not simply a case of pushing harder. When we train the thresholds for these “safety switches” raise, allowing us to lift more. This is partly because our muscles become more conditioned and less susceptible to damage but also because our overriding mechanisms improve. We can prove this theory by using a simple maximum voluntary contraction test on a muscle. An athlete produces their strongest contraction and when it peaks we add extra stimulus externally with an electric impulse. The peak will increase significantly higher than voluntary stimulus could achieve, proving there is more force possible.

So how do we increase strength? There a couple of areas which can be improved. First we need to train the movement. Becoming more accustomed to the movement helps us learn the pattern of muscle activation required to perform the action effectively. Second we must improve stimulation and muscle activation. The obvious method is working closer to our maxes which in theory requires a “close to max muscle contraction”. Become accustomed to producing maximum force will improve the mechanisms involved over time. This can be taxing on both the central nervous system (CNS) and the muscle structure itself. It will require structural recovery which takes time. Speed training is an excellent variation as it allows us to improve the rate of impulses coming from the brain. More ballistic type exercises such as jumping are a good way to improve rate of neural transmission. Adding bands or chains to sub-maximal weights for particular lifts can also be another variation to include. The increased resistance over the range of the movement requires an accelerated contraction.

Adding chains can be very effective at improving neural components involved in strength. Photo source: www.clintdarden.com

Adding chains can be very effective at improving neural components involved in strength. Photo source: www.clintdarden.com

These types of training are excellent ways to improve the neural component of strength without needing any structural recovery. They are demanding on the CNS and as always adequate recovery is necessary. The next area to work on is increasing muscle mass. This involves hypertrophy of the muscle fibers which occurs over a much longer period of time.

Becoming strong is important to all athletes but understanding what makes them strong can be just as important. The body adapts quickly and so a multidirectional approach can help progress in terms of consistency. Often athletes employ the maximal lifting approach exclusively and plateau quickly. Combining different methods over a periodised training plan can make sure that an athlete continues to improve in the long term and achieve full potential.