Why running is harder when it’s hot outside

It seems to be a lot easier to get out of the front door when the weather is warmer, the days are longer and the clothes are lighter.  So much easier than the cold, dark winter nights when sometimes just moving was an effort due to the number of layers you had to wear.

So why is it harder to run in the heat? The combination of running and being exposured 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.  Your body may not be able to cope with this and as a result your internal temperature may rise to a dangerous level which results in heat exhaustion.

The warning signs of heat exhaustion are feeling faint, dizzy and disoriented; if you become seriously fatigued, it is best to stop running straight away.


Tips for running in hot weather

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.

Place a couple of water bottles in the freezer, one to take out running with you and the other to come back too once you’ve finished.

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 you could pop a bandana in the freezer before you run and pop around your neck just as you are heading out.

Run at the coolest time of the day

Either run before the sun rises or in the evening as the sun sets.  Try and avoid running during the middle of the day when the sun is at its hottest. The air quality is also at its best in the morning, making this an ideal time to run. Cool down your body before you set out by having a lukewarm shower first thing in the morning

Change your routes

Try and run along shady routes, off road running is great during the summer months as tress offer more shade

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 minimized putting you at a higher risk.

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; look out for the signs of heat stroke. Remember, the first two weeks of running in the sun should be enough time for your body to adjust. 

Let your body temperature gradually return to normal, spray yourself with water and drink a



Warm up followed by the running drills.  Try to take the emphasis off time now and focus on how you feel and what your breathing sounds like so that you are in control of how much you do.  Walk whenever you want, slow it down, even if you think you could walk faster, you are still running so be kind to yourself and take it steady.  You might surprise yourself.

 Aim to be out running for 35 mins and if you have any questions then please just ask.