Medical newsletter
Dear Runner,
The sixth edition of the Venloop is coming soon. On 27 March, thousands of runners will start their race again to bridge 10 or 21.1 km distances. A task that is not to be underestimated! With events like this, the risk of injuries or other medical problems is higher than with regular running training. As Venloop medical partner, the Sport Medical Advice Centre ‘Vitaal’ offers a number of tips and useful pieces of information for participants to be able to appear at the start in optimum condition.
Weather
Weather conditions may have a great impact on the functioning of the body and, therefore, on the runners’ capacity to perform, and certainly so if they have not taken the proper precautions. Factors that may have an impact are temperature, wind and humidity. Participants are well-advised to keep a good eye on the weather forecasts before the race and to act accordingly. Here you should think of sufficient clothing in wet and cold weather. At the end of March, the weather is (usually) chilly and wet in the Netherlands, but there is also the possibility of warm and sunny weather. Furthermore, it is important to check your fluid balance well. In general, the effect of a warm sunny day is much stronger if the preceding period (in which the training was done) was much colder.
Fluid
An endurance sportsman’s fluid balance is very important. During a half marathon, a runner, through sweating and urine production, often loses more than 3% of his/her body weight. Already from 2% fluid loss (for the average runner this is ‘only’ 1½ litres), a measurably reduced capacity to perform can be established. In more extreme cases (>6% of the body weight), exhaustion, unconsciousness and even coma and death may occur. Every year, runners and other endurance sportsmen are hospitalised – especially during the summer months – as a result of a shortage of fluid. For endurance sportsmen, therefore, it is important to take in sufficient fluid during the race. However, an excess of fluid intake may also lead to problems during a half marathon. Excessive drinking of only water may cause a relative salt shortage in the blood, which may also lead to reduced capacity to perform and (serious) health risks. Consequently, it is highly important for runners to not only pay attention to the right quantity but also to the right composition of what they drink during the race.
What is the right quantity? In general, it may be argued that drinking when you are thirsty will not lead to serious dehydration or a shortage of salt. The case, however, is that thirst does not occur until there already is a water shortage and there may be reduced capacity to perform due to a shortage of fluid. For that reason, it is better to drink en route also even if runners are not thirsty. The average need for fluid during intensive endurance efforts is approximately 750 to 1,000 ml per hour.
However, some comment is called for here. In warm weather with high atmospheric humidity, runners lose more fluid and the risk of dehydration is higher. As the duration of the effort increases, the risk of excessive fluid intake and, with it, a relative salt shortage, is higher. During the Venloop, there will be drinking stations every 5 km to give the participants the opportunity to drink sufficiently.
Nutrition
At least equally important in endurance races is nutrition. The most important fuel during intensive efforts is carbohydrates. Carbohydrates are stored in the liver and the muscles. On average, the supply present is sufficient for about 60 - 90 minutes of effort. To acquire a maximum carbohydrate supply, you may eat slightly more carbohydrate-rich meals (cereal products, pastas, rice, sweets) a few days before the marathon. These meals are most effective if you eat them after the training. In this period, training runs should no longer be exhausting.
In addition, it is important to replenish your energy supply during the marathon. Try to do this also by means of carbohydrate-rich foods such as energy bars. A good guideline is eating approximately 1 gram of carbohydrates per kg body weight per hour. For an 80-kg runner, therefore, this amounts to 80 grams of carbohydrates per hour. The body cannot absorb more than this amount of 60-80 grams of carbohydrates per hour. An excessive amount of carbohydrates will retain fluid. This may lead to diarrhoea and prevent a quick absorption of fluid from the intestines. Research shows that carbohydrates in liquid form are absorbed far better than in solid form. The average commercial thirst-quencher (sports drink) contains, per litre, exactly the amount of 60-80 grams of carbohydrates that can be absorbed by the body during exertion. It is not wise to take in energy drinks already during exertion, as their carbohydrate (sugar) concentration is far too high. The effect often is that the drink remains in the stomach or the intestines for a long time, causing nausea and/or diarrhoea. Because fluid and carbohydrates need some time to be absorbed from the stomach and the intestines into the body and become available for combustion in the muscles, the intake of fluid and energy at the beginning of the race is far more important than at the end.
Injuries / illness
Injuries occur in every sport, also, therefore, while running a 10- kilometre race or half marathon. Below is a list of the most common problems that may occur.
- Skin problems
One of the most frequent problems in a marathon is the occurrence of blisters and/or grazes. The running pressure inside the shoe may cause the foot to rub, resulting in blisters and grazes. If you notice you are being troubled by this, please report to the nearest first aid station to have it treated.
- Muscle and tendon complaints
Muscle and tendon complaints are a frequent phenomenon as well. They may range from a pulled muscle to, for instance, excessive stress of the Achilles tendon. Tendon complaints usually concern a recurrence / worsening of an already existing complaint. If you incur an injury, it is not wise to continue running with it. You will then run the risk of aggravating the injury to such an extent that you may put yourself out of action for a long time. If you incur an injury, the best thing for you to do is to report to the nearest first aid station.
- Muscle spasm and illness
Muscle spasms mainly occur after the finish and often they are a sign of exhaustion or a shortage of fluid. After a recent illness, especially if it was accompanied by fever, in the period of the last two weeks before the start of the race, it is not wise to participate in a running event without expert advice. The same is true for doubts about injuries.
- Acute heart death
Fortunately, heart complaints and acute heart death very rarely occur to sportsmen! Consequently, the risk of you getting heart problems during a half marathon is small. Still, there are a few runners in the Netherlands every year who do get heart problems during a race. If you notice one or more of the symptoms below, you had best report to the nearest first aid station for an assessment.
The symptoms are:
shortness of breath (other than conditionally determined)
pain in the chest, sometimes spreading to an arm or to the throat or jaw
palpitations, irregular heartbeat
dizziness / inclination to faint
In the event of injuries and other medical problems during the race, the medical staff present will advise you on the possibility of continuing the race with the problem that has come to light. In some cases, the medical staff may give the organisation binding advice to take a runner out of the race. Of course, this will only happen in case of defects posing a serious threat to the runner.
Contact details and medical information
If you know you have medical problems and/or use medication, then, for the purpose of providing proper en route care it is important for you to carry some information about your disease or about the medication you use. All runners are well-advised to write their contact details on the back of their bib numbers, (name, address and contact person’s telephone number), so that in the event of a calamity first aid staff know who to notify or who obtain information from.
Sportsmen who would like to find out more about the possibility of a sports medical examination or who are faced with injuries in the run-up to or after the finish of the Venloop and want to seek expert advice on them, can contact SMA-Vitaal via +31 (0)478-522777 or www.sma-vitaal.nl. Here you will find all information regarding sports medical examinations or injury consultations.
We hope you enjoy the 6th Venloop and we wish you much running joy.
Rob Eijkelenboom, SMA-Vitaal sports doctor
VieCuriVitaal Medical Team
