You must be fit and well to run 13.1 miles. Please do not take any chances with your health. Severe exertion during or soon after any kind of injury or illness is extremely dangerous. If you find yourself in this situation, do not take part. Please read the following advice from our Medical Director, Professor Sanjay Sharma.
Before you take part in The Big Half, discuss any potential medical problems with your general practitioner (GP). The advice that follows here supplements anything they may say. Make sure you see your GP if you have a problem that makes it a risk to run a half marathon.
We are happy for people with serious medical conditions to run the half marathon, but only with their GP’s or specialist’s agreement. If you have a medical problem that may lead to you having a blackout, such as fits or diabetes, put a cross on the front of your running number and write the details, especially your medication, on the reverse of the number using a permanent marker pen.
If you have a family history of heart disease or sudden death, or you have symptoms of heart disease – such as chest pain or discomfort on exertion, sudden shortness of breath or rapid palpitations – see your GP, who will be able to arrange for you to have a proper cardiac assessment.
Muscular aches and pains often occur after an increase in training, so aim to increase your training gradually so that you do not suffer prolonged exhaustion. You should also intersperse days of heavy mileage with one or two days of lighter training, so that your body can replace its fuel (muscle glycogen).
Rest days are also important. If you have flu, a feverish cold or a tummy bug, do not train until you have fully recovered. Once you feel well again, start gently and build up gradually. Do not attempt to catch up on lost mileage after illness or injury as this may cause further damage or illness.
To reduce injury risk, train on soft surfaces when you can, especially on easy training days. Vary your routes; do not always use the same shoes and run on differing cambers, hills, etc. Always face oncoming traffic, especially in the dark.
You should always aim to replace fluids lost in sweat otherwise your body will become dehydrated and less efficient. Remember that alcoholic drinks are dehydrating: a pint of beer produces more than a pint of urine, while spirits have an even worse effect. Take on board plenty of non-alcoholic drinks, especially before the event and in hot weather. Drink enough to keep your urine a pale straw colour.
Drink plenty of liquids after training, especially long runs, and drink during events, especially in the first half of a marathon. Practise drinking during longer training runs. Drink plenty of fluids and reduce alcohol intake in the two days before the event. But do NOT drink excessively just before the event.
Eat what suits you. Large doses of supplementary vitamins and minerals (such as iron) are not essential and produce no benefit if you are on a good, varied diet, but additional vitamin C in small doses is reasonable when fresh fruit and vegetables are in short supply. Training helps you to sustain a high level of muscle glycogen if you eat a lot of carbohydrate. If you can, eat within two hours of your long runs and the end of the half marathon. This helps to replace the muscle glycogen more quickly and speeds recovery.
Do not change your normal diet drastically in the last week before the half marathon but decrease your intake of protein (meat) and increase your intake of carbohydrate (pasta, bread, potatoes, cereals, rice and sweet things), especially for the last three days when you should also be markedly reducing your training. This loads the muscles with glycogen. Unless you reduce your protein intake you will not eat enough carbohydrate. (Not all runners are helped by first depleting carbohydrate with a long run and low carbo diet and then loading – this can make your muscles very heavy.)
When training outside in the dark, aim to wear kit that will help you to be seen. White clothing, reflective flashes on your arms and legs and LED lights or a head torch will help motorists to spot you in dark or gloomy conditions. On Event Day, wear shoes that you know from experience will not give you blisters.
On Event Day
Do not run The Big Half if you feel unwell or have just been unwell, even if you are raising money for charity. Most medical emergencies occur in people who have been unwell but do not wish to miss the event. If you feel feverish, have been vomiting, have had severe diarrhoea or any chest pains, or otherwise feel unwell, it is unfair to you, your family, your sponsoring charity and the event support staff to risk serious illness and become a medical emergency. You are also unlikely to do yourself justice. There will be many other events.
Wear appropriate clothes for the weather on Event Day. On a cold, wet day you may become very cold if you reduce your running pace or walk. A hat and gloves will prevent heat loss and are easy to carry.
If it’s hot on Event Day, wear loose mesh clothing, start slowly and, if possible, run in the shade. Don’t be greedy and pour bottles of drinking water over yourself; you may be depriving slower runners of much needed fluid.
Drinking too little on Event Day can lead to problems, as you need to replace some of the fluid you lose as sweat. Drinking much too much can also be very dangerous and lead to hyponatraemia, fits and even death in the marathon and longer distances, but sensible fluid intake is necessary even for a half marathon. Start the event well hydrated (remember that your urine should look pale) and drink when you can, especially in the first half of the event when you may not feel very thirsty. This will help you to feel better late in the event and may prevent cramp. Cramp is most common in runners who have not trained sufficiently or are dehydrated.
Do NOT gulp large volumes of electrolyte-free fluids (like water) before, during or after the event. It is possible to become ill from drinking too much, too quickly. There are frequent water stations, but you do NOT need to drink at each one, just swallow a mouthful of water occasionally. If you like Lucozade Sport, drink that as well. Do NOT drink excessively after you finish the half marathon. You can only rehydrate gradually, so aim to have some salty food as well and you will not get hyponatraemia.
The 2007 London Marathon was the hottest in its history and was sadly noteworthy for the death of 22-year-old David Rogers from hyponatraemia. There were 12 other cases of hyponatraemia the year before, six of whom required emergency treatment in hospital. Again, it is likely that all of these drank more than necessary for the hot conditions, despite the official advice given by the London Marathon on safe drinking during the event.
The 1996 London Marathon was run on a similarly hot day and while there were complaints about the water running out, we had no significant cases of hyponatraemia. In 2003 there were plenty of drinks available for what was another warm marathon day but on this occasion there were 15 hospital cases of hyponatraemia. Many runners are drinking too much! The adidas Silverstone Half Marathon has plenty of drinks stations to ensure there is enough for everyone, including the slower runners at the back.
You do NOT need to drink at every water or drinks station. THINK before you DRINK.
At the Finish Line
Once you cross the Finish Line, do not stand around getting cold. Keep walking, especially if you feel dizzy, and have a drink to replace lost fluids. Go to the baggage area as soon as you can, collect your belongings and change into warm, dry clothes. Keep on drinking slowly and have something to eat. Some runners feel faint more than half an hour after finishing the event, often because they have taken insufficient fluid and/or not eaten anything. Again, do not drink excessively after the event.
Advice on performance-enhancing agents
Adequate preparation for a half marathon requires appropriate nutrition, hydration and rest. Athletes often consume isotonic, protein and carbohydrate drinks as well as energy gels and bars purchased in sports and health food shops in preparation for the event, which is considered safe practice.
However, over the last two decades there have been an increasing number of commercially available compounds that claim to enhance performance. Some have been found to contain substances banned in other countries and other products (such as steroids) that are banned for use among competitive athletes. Such products are usually purchased via the internet and should not be used by anyone training for a sports event.
Runners using performance-enhancing compounds that have not been licensed and regulated properly may experience serious side effects and increase their risk of developing heart disturbances that culminate in sudden death.
There have been well-publicised cases of runners inadvertently using compounds in an attempt to help them fight fatigue during endurance events and this caused detrimental effects on their health, resulting in their death.
In one recent case, toxicology identified traces of DMAA, which is an amphetamine-like substance. Although banned in sport, the product was legally available at the time and advertised as a powerful performance-enhancing agent and the warnings associated with the potential harmful ingredients were not highlighted on the product. Runners should avoid consuming unregulated substances bought via the internet.
Train sensibly. Follow this simple advice and you are unlikely to need medical aid. If you do, there are St John Ambulance points throughout the course and at the Finish Line. There will also be a medical director and full medical team in attendance on Event Day.