Feeling sick is a sure-fire way to take the shine off a great day on your bike. Nausea at the end of a ride is often cited as a sign that you’ve given it everything — particularly during racing. If nausea comes on before the finish, it can have a negative effect on your performance, wasting all your effort. But what causes cycling-induced nausea and how can you prevent it?
Food, dehydration, overheating, low blood sugar and anxiety can all contribute. Food has an important impact. A Japanese study in 2001 showed that nausea is worse when exercising hard right after eating. Not that exercising on an empty stomach is recommended either — athletes who fasted before exercise also suffered, possibly as a result of low blood sugar.
Dehydration can aggravate nausea, as electrolytes in the blood become imbalanced — particularly sodium. During a hard effort or overheating, it’s thought that blood is diverted from the stomach to the working muscles and skin, upsetting normal gastric function. Pre-race nerves don’t help and nausea is a symptom of anxiety.
Six ways to prevent nausea
1. Eat smart
Eating a small, easily digested meal 60 minutes before riding is recommended.
2. Hydrate in advance
Make sure you’re well hydrated by drinking 5-10mls of fluid per kilo of bodyweight, two hours in advance.
3. But don't drink too much
Drink when you’re thirsty, to maintain hydration, but avoid consuming too much liquid as it can make things worse.
4. Dress for the conditions
Wear suitable clothing for the conditions and acclimatise before racing when it’s hot.
5. Ride at your fitness level
Symptoms should improve with general fitness, but if sickness is a major issue, reduce your effort and build up gradually.
6. Be prepared
You can lower your anxiety levels through preparation — leave nothing to chance, especially when racing.