Alison Patterson, Advanced Sports Dietitian
Evening runs are usually hotter than morning runs – especially if training in the heat of Summer. The good news is that there are a number of nutrition strategies you can try around training and racing to help cool your body and slow the rise of your core temperature. In doing so, this should help delay fatigue and allow you to sustain your intensity and pacing for longer. Give these tips a try to feel the difference they can make to your performance.
Sweating is the body’s main way of cooling core temperature. But in doing so, fluid is lost from the body, which can make regulating your body’s core temperature more difficult. It’s important to start every run appropriately hydrated – aiming for light yellow coloured wee before you run is a good starting point.
Know your sweat losses
Most people know that you need to drink fluid during exercise to replace what is lost from sweat. What is often less clear is exactly how much and what type of fluid is best. There’s no ‘one-size-fits-all’ approach when it comes to hydration, as fluid needs are highly individualised depending on each person’s sweat rate. Using your thirst as a guide can be a useful starting point, but the best way to avoid both dehydration and gut upset is to undertake a sweat testing assessment. This can then be used to determine a hydration strategy to meet your specific needs.
Electrolytes are important
Drinking sodium (salt) containing fluids when exercising in the heat can aid fluid absorption through the gut and retention of fluid in the body. Depending on your fuel needs you may find sports drink a useful option. Alternatively, if your carbohydrate requirements are low, electrolyte sachets or tablets offer the benefits of salt without unnecessary fuel.
There’s nothing worse than trying to down a warm bottle of water when the sun is beating down on you. Avoid this by adding ice cubes to your drink bottle or hydration backpack so that by the time you’re ready to drink it, it’ll still be refreshing and cool.
If you haven’t tried it already, pre-cooling your body before starting training or racing in hot weather can be fantastic! Pre-cooling can reduce your body temperature before you start exercising and slow the rise in temperature once you’re running. There are several ways of pre-cooling including ice-baths, ice-vests, cooling jackets, but one of the easiest ways is by drinking a slushie (semi-frozen icy drink) before you start. You can make your own by freezing a ready-to-drink sports drink and taking it out an hour or two before you want to drink it to allow it to semi-melt.
While not strictly a nutrition strategy, putting ice from aid stations under your hat or tipping iced cold water over your head are other ways that you can actively cool your body during exercise.
Of course, whenever you are exercising in the heat common sense and listening to your body are essential. Avoid exercising in the heat of the day, seek out shade and be aware of early warning signs of heat illness. Nausea, headaches, vomiting, dizziness and fainting are all red flags that you need to stop and cool your body down before you get even more unwell.
If you’d like to know more about nutrition for your individual situation, please don’t hesitate to get in touch with Ali (http://www.alisonpatterson.com/). You can also like her Facebook page for regular tips and recipes https://www.facebook.com/alisonpatterson.sportsdietitian/