A special method to improve oxygen transport
Athletes with spinal cord injuries are consciously able to induce an autonomous dysreflexia with the sole purpose of improving performance. Consciously generating autonomous dysreflexia is known as ‘boosting’. According to the test subjects in a study of Burnham, 90 to 100% of contest athletes with a high paraplegia use this method. Paraplegic athletes are convinced that boosting is an effective method to improve performance. By boosting they not only feel more alert and fitter, also a significant improvement in performance after boosting was objectively determined. In a race over 7.5 km the participants performed about nearly 10 percent better with a faster time after boosting
THE AUTONOMIC NERVOUS SYSTEM
The autonomic or involuntary nervous system controls all sorts of organ functions through a harmonious interplay between the sympathic – and the parasympathetic part of the autonomic nervous system. Thus, the autonomic nervous system controls respiration, digestion, heart rate, temperature, blood circulation and so on.
Under normal conditions, the interplay between sympathetic and parasympathetic ensures the perfect functioning of all these complex and vital systems.
The sudden sympathetic over-stimulation leads to cross lesions above the level of the 6th thoracic vertebra (TH6) to a narrowing of the arteries in the entire gastrointestinal region. Due to the narrowing blood vessels a considerable volume of blood is flowing out of the gastro-intestinal area to the working muscles. More blood means a greater oxygen supply and an increase in performance of the muscles.
This manipulation is not completely harmless because the blood pressure may rise to very high values.
PROVOCATION OF BOOSTING
Athletes with a lesion above the level of the 6th thoracic vertebra generate an autonomous dysreflexia by ensuring a full urinary bladder, a tight band around the legs or by sitting on a sharp object in the wheelchair. The incentives created induce a sympathetic hyperactivity which leads to an emission of noradrenaline and an extensive narrowing of the blood vessels in the stomach and bowel.
By ‘boosting’ VO2max significantly improved by almost 20 percent compared to the race without boosting. The increase in VO2max can be explained by an increased oxygen uptake by the working muscles which might be explained by incorporating a considerable volume of blood from the gastro-intestinal area moves to the active muscles.
The significant rise in blood pressure can cause arrhythmias of the heart and premature atherosclerosis. Periods with high blood pressure can lead to visual disturbances, seizures, strokes and heart attacks. During ‘boosting’ there is a risk, due to the narrowing of the arteries below the lesion, and due to the increased heat production by muscular work, of overheating. Many athletes elicit the autonomic dysreflexia by stretching of the urine bladder. The stretching of the urinary bladder is done by drinking large amounts of water. In addition to damage to the urinary system, there may be a water intoxication occur with nausea, vomiting and the emergence of a sodium deficiency in the blood. Sodium deficiency can have cardiac arrhythmias and irreversible brain damage as a result.
CONSEQUENCES OF BOOSTING
Through experience the wheelchair athletes became clear that training with autonomic dysreflexia and riding competitions was much more fun and that the performance improved significantly. All athletes at international level are familiar with the beneficial effects of boosting.
It even seems that athletes with a lesion above the level of the 6th thoracic vertebra known as ‘boosting’ have to use this method in order to make still any chance of a reasonable classification or victory.
The International Paralympic Committee considered boosting as dangerous for the health of the wheelchair athlete and qualifies ‘boosting’ as unethical and illegal. The IPC has also introduced checks to detect boosting. All paraplegic athletes with a lesion above the level of the 6th thoracic vertebra (TH6) may be subjected to a medical check before and during matches.
They are checked for blood pressure, heart rate, sweating, presence of spots on the skin, chills, shortness of breath and trembling. An athlete with suspicious symptoms or a combination thereof, gets a start prohibition.
But it is fairly easy to generate an autonomous dysreflexia yet after the medical examination. The imposed obligation that athletes have to empty their urine bladder before the competition is a rule that is uncontrollable.
Because boosting never can be checked properly, it would be much better to look for opportunities to elicit autonomic dysreflexia in a non-traumatic and controlled manner. Such an application can benefit the entire population of people with spinal cord injuries. Some people with a high spinal cord injury feel more alert and fitter during autonomic dysreflexia, for example by the increase of blood pressure. Increased knowledge of autonomic dysreflexia may lead to an improvement in the quality of life of people with a high spinal cord injury.
Another aspect is that the rules against “boosting” may be exaggerated. Sports nowadays do bring risks that can often be very serious. Think of boxing, motorcar racing, cycling, mountaineering and many other sports.
Also in weightlifting blood pressure may be, as in boosting, alarmingly high. Against this rules were never established to protect the athletes.
Moreover, boosting is a completely natural process. Before autonomic dysreflexia is generated in a controlled manner, educating of the athletes with high spinal cord injury, their coaches and other stakeholders on the mechanism and the dangers of boosting, is essential.
The drafting of more prohibitions, the rigorous control, followed by increasingly severe punishments is the standard Pavlov reaction of international sports federations. That is the worst choice that you can make and it does certainly not bring the solution to the “problem” any closer.