Medical advice

Good preparation is very important to participate the NN Marathon Rotterdam in a responsible way. It is important that you listen carefully to your body during and after your run. On this page you will read all the advice that will help you to enjoy the NN Marathon Rotterdam well prepared. 

Medisch advice

Good preparation is essential to participate responsibly in the NN Marathon Rotterdam. This preparation often starts weeks, if not months, before the start. Take a look at what you need to take into account during your preparation.


Health problems

If you have problems with your health, which pose an increased risk of cardiovascular diseases such as obesity, high blood pressure, high cholesterol, diabetes, pre-existing cardiovascular diseases (or common in the family), or if you have frequent injuries, we recommend a sports examination at a Sports Medical Advice Office (S.M.A.) or sports clinic.

On this ( website you can find more information about examinations, ways of testing and possibly also fill in a questionnaire (including a cardiovascular questionnaire). After filling in this list, you can determine whether it makes sense for you to have a cardiovascular medical examination.

Clothing and weather

- Above 15°C (and at least 20°C) you should dress in light ventilating clothing, otherwise the body will not be able to get rid of the heat and there is a risk of heat build-up (note: no cotton, this will retain moisture).

- In cold weather (5 °C and for slower runners 10 °C) a thermoshirt on the skin is the best choice. Wear a thin, ventilating layer (no nylon). A hat is recommended for low wind and wind.

Note: The slower your pace, the more clothing you need (except at temperatures around 20°C). At a slower pace (walking) there will be considerable cooling down. The wind chill temperature is mainly dependent on wind and humidity. When the temperature is +10°C with a moderate wind (approx. wind force 5), it feels like +4°C. However, if it is 5°C with a moderate wind, it feels like -4°C. Often in the afternoon the temperature drops by about 5 to 6 °C, which causes us to see much slower runners cool down. Always tie your laces thoroughly with a double knot, so they don't go loose during the race.

Running schedule

Create a running schedule tailored to the event you are participating in.

Do you need help with your running schedule? Then take a look at our training tips!


Walk only on well run-in shoes and socks and pay attention to the road surface during every training session and race. Alternate left and right walking on the road when possible.


Do you have a feverish disease (> 38 °C) prior to the event (approx. two weeks)? Then don't run!

Before and during your run

The day of the event has arrived and you come well prepared to the start. For a successful participation it is important to take several factors into account just before and during the run. Read the advice on the right carefully, this way you leave nothing to chance.



The amount you drink depends individually on the weather and perspiration. Drink extra up to 45 minutes before the start, then stop drinking and make sure you visit the toilet. Take a bottle (approx. 300 ml) into the starting area and drink it 5 to 10 minutes before the start. This will prevent you from having to pee on the way.

A feeling of thirst is never a good indicator. If you are not used to drinking, drink 100 to 200 ml of water every 15 minutes. Carbohydrate containing drinks 5-8% are also suitable. Make sure you take in about 70 grams of carbohydrates per hour throughout the race. Bottles of measured sports drinks (on your belt) can help.

If the weather is cool or the runner is slower, take energy drinks instead of solid food or fruit. These stay in your stomach too long. The weight difference between before and after the run of more than 1 kg is equal to the amount of fluid you drank too little. So try this out during workouts.

Listen to your body

If you don't feel well, stop immediately. The first symptoms of dehydration are goose bumps on the chest and upper arms, chills, pressure in the head, dizziness, muscle cramps, vomiting and dry skin. These symptoms can quickly turn into disorientation and confusion.

Have you ever had problems with dehydration and/or too high a temperature, then you have a greater chance that the weather will happen (especially in warm weather). Then don't walk any further, failure is no disgrace!

Calf cramp

If you have calf cramps, walk slowly or walk and stretch lightly if necessary. Don't stop, but drink extra. Beware of dehydration

Start off easy

Start quietly and check your pace. Every second per kilometer too fast at the start of the race can result in minutes lost per kilometer at the end.

Walk at your own pace and avoid tempo increases and sprints in the final kilometers..

Stop with these symptoms

Stop in case of chest pain, abnormal shortness of breath and/or dizziness.

Pay attention!

Pay close attention to the road surface and other situations around you.


Apply Vaseline to nipples, thighs and other abrasions.

Carrying medical information

Medical information about diseases (such as diabetes or medication) you should carry with you. Mention this on the back of your starting number. Also write down the phone number of a contact person who can be reached during the race. Mention your name, address and phone number here as well.

Urgent questions just before the event

If, despite good preparation and reading the medical information, you still have urgent questions about training, injuries, nutrition, etc., we advise you to contact your family doctor.