While the summer can do wonders for motivation, offering up longer daylight hours for earlier morning runs and later evening runs, not to mention shorts and t-shirts weather, it can also, even in the UK (even in Scotland), present conditions that can cause a runner to overheat.
Anyone who has spent time training by heart rate knows that summer lunch time runs present slower paces in zone two than on winter evenings. A windless, humid day in the middle of summer, while delightful to the soul, can make it difficult to get the best performance out of your body.
The basic science
How the body works to keep you cool
When you start to exercise, your body generates heat through movement, and you’re also producing energy, which in turn generates more heat. In cooler and more temperate conditions human beings are exceptionally well-adapted at regulating the resulting rise in core temperature.
Our main thermoregulation system is through sweating. Blood is diverted away from the working muscles to the skin, sweat evaporates from the skin and cools down the blood, which is then recirculated back around the body. This keeps our core temperature in a steady working range.
How the heat affects your running performance
But as the temperature rises, that thermoregulation system becomes less and less effective. Additionally, solar radiation, humidity, and our perception of heat can all combine to raise our core temperature above that steady working range. As our core temperature rises beyond a critical level, we see a decrease in performance, and as runners, we slow down.
Where that critical point is varies from runner to runner and physiology to physiology.
In this article, I’m going to highlight a number of quick ways you can combat the heat this summer to put yourself in the best position to train and race when the mercury hits its highest points.
8 heat hacks
This is exactly what it sounds like. Overheating is a gradual process, so the further removed you are from that critically high temperature when you start your run the better a position you’ll be in at the end.
You may have seen some athletes on TV wearing custom-built ice vests before shorter events to cool down their core temperatures while still allowing them to warm up their muscles. A buff or ruff around the neck folded to hold ice-cubes is a very cost-effective way of gaining a similar effect. In a pinch, even running your singlet or shirt under cold water would count as a pre-cooling method that would start your body at a lower core temperature.
2. Ingest ice or a slushee-style drink
The phase change from ice to water does an amazing job of drawing heat from your core temperature, so ingesting ice, or ideally, a slushee-style beverage mid-run will do a great job of preventing you from overheating.
To be clear, that’s not the syrupy blue kind you get at the cinema. Just something that’s part way between ice and water. It’s very easy to drink but still allows you the cooling benefit of the phase change.
Unless you’re running a crew-supported event or you’re a professional athlete, you’re most likely not going to have access to ice and slushee drinks during a race, let alone on a training run. This technique could be bought into pre-cooling, sipping on a slushee just before starting, or even having a friend pass you one early in the run.
3. Wear a cap
In addition to using a sweat-resistant sun cream with an SPF of 30 or higher, a lightweight summer running cap will be moisture-wicking, protect your head from the sun’s rays, and give your face (or neck) a bit of shade, making you marginally cooler.
This will also feed into your perception of how hot or cool you are.
4. … and pair that with some sunglasses
The sunnies won’t directly cool you down but they’re almost a must-have for summer running. Having the full-brunt of the sun’s glare shoved down both eye holes because you ran past a tree’s cover or a cloud moved at just the wrong moment sucks, can slow you down, and will massively increase your risk of tripping or rolling an ankle.
5. Skin wetting (but not when you think)
When you feel like you could burst into flames from how unfathomably hot you’ve gotten in a race or a long training run, it’s intuitive to submerge yourself in a burn (or a brook), or empty a bottle of water over your head to help cool yourself down.
While that will certainly help at that stage, the painful truth is it probably could have been avoided.
On a hot run, if you find yourself on a long descent, or running through some shade, and you feel the sensation of having cooled down, you’ve probably stopped sweating. But you’ve still been running, so you’re probably still operating at a near critical core temperature.
Then is the time to jump in the burn or empty a bottle over your head. You know once you’re exposed to the sun or back on the climb it’s going to feel toasty again. Prevention beats the cure.
6. Carry water to stay hydrated
Carrying water is a too-often overlooked staple of summer running.
Drinking helps you to maintain plasma volume in your blood, and so keeps the blood moving to the working muscles. Also bear in mind that sweating draws from intracellular to extracellular fluid in the body, so taking on water while you exercise in hot conditions, especially for longer periods, is essential.
Decide how best to carry your water while running by reading our backpack, hydration vest or running belt article here.
7. … and throw an electrolyte tablet in there while you’re at it
Electrolyte tablets are also an anti-diuretic, so will actually help prevent extra fluid loss through peeing.
And just in case you were wondering, neither Nuun nor High 5 electrolyte tablets include any artificial preservatives.
8. Consider investing some time in heat training
So not really a hack, and something that will take a little time to implement and benefit from, but a simple and easily incorporated practice for any recreational athlete who wants to perform at hotter races.
Incorporating heat training into your plan while utilising the heat hacks in this article will give you the best results when it’s time to smash that A-race abroad… you know, the one you booked in the country where summer’s almost as hot outside as it is in the bath.
Listen to our podcast on heat training for the everyday runner for further info and advice.