Why running is harder when it’s hot outside?

Why is it harder to run in the heat? The combination of running and being exposed to the sun makes the body work harder to regulate the body’s core temperature. Blood has to cope with a dual role, it must cool the body by transporting heat to the skin’s surface and supply oxygen and fuel to the working muscles.  If you exert yourself too much in the heat then your body may not be able to cope resulting in an internal temperature increase which may result in heat stroke.

The warning signs of heat exhaustion/stroke are feeling faint, dizzy, disoriented and serious fatigue.  Here’s how to maximise your safety when running in hot weather.

1.     Hydrate well

Drink before, during and after runs to replace any lost fluids, because you are losing fluids through sweating you need to keep well hydrated; sweating is the body’s way of cooling the body.  Sweat consists mainly of water but it also includes other nutrients such as sodium, chloride and potassium, you can easily replace all of these nutrients by hydrating with a sports drink. Try not to wait until you are thirsty before you have a drink, drink before you become thirsty. Walk through the water stations and have a drink if you are not used to carry a drink with you on your runs

2.     Dress cool

Lightweight and breathable fabric that wicks sweat away is the best option when running in the summer months. A pair of shorts, vest top and socks are the best options; you need to maximise the exposure of the skin surface so that sweat evaporates. Avoid cotton T-shirts as this material absorbs sweat and this will make the t shirt heavy and uncomfortable. Try and wear a cap or pop a bandana in the freezer before you run and place around your neck just as you are heading out.

3.     Wear sunscreen

Wear a high factor sport sunscreen as skin that is sunburnt loses its ability to sweat therefore your ability to keep cool is minimised.


4.     Adjust your expectations

Start slowly on your runs, run at a steady pace that feels right for you and avoid worrying about how fast or slow you are going.  You need to also be prepared to adjust your pace during the run as well, expect to feel more tired than usual as the heat zaps your energy. Run on how you feel and listen to your body and look out for the signs of heat stroke. Let your body temperature gradually return to normal when you return from your run and cool down by spraying yourself with water.


How temperature can affect pace

How temperature can affect pace