There’s nothing more frustrating than training hard for months only to face unexpected heat on race day. Racing in hot weather significantly increases fatigue, dehydration risk, and overall physical stress as your body works harder to stay cool.
Whether you’re preparing for a summer race or caught off guard by an unseasonal heatwave, we’ve got you covered. Here are our top tips for racing safely in the heat, including how to manage your pacing, stay hydrated, and perform your best in challenging conditions.
Manage Expectations
First of all, set yourself up for success. If you know you’re racing in the heat, take a conservative approach when it comes to setting pace targets. If you’re aiming for a personal best time, but the weather is forecast to be much hotter than expected, you may have to adapt your goals slightly so that you're able to run safely.
If you’ve been training hard for a goal time, it can feel really disappointing to lower your expectations, but it is important to remember that you can only control the controllable. Whilst it's so tempting to stay committed to your goal, blasting off at PB pace in unexpectedly hot conditions will not only lead to burn out, but can also be really unsafe if your body is not used to working hard in high temperatures.
Coach Steph says: "If you were aiming for a PB, then don’t forget that this is the fastest you have EVER run in your whole life. It's not realistic to be able to do this every time we race, especially not in adverse conditions."
How to Manage Your Pacing In the Heat
Dial back your pace in the first half: Starting steadily helps reduce the shock of running in the heat and prevents you from burning too much energy too soon.
Heat stress is already at work: Even if you don’t notice it, the heat is already affecting your body. The effort your system is putting into cooling itself can be masked by adrenaline at the start. Keep it steady.
Save your push for later: If you feel strong in the second half, that’s the time to gradually build pace and finish well.
You can adjust your pace targets on the Runna app if you are expecting hot conditions. Personalised pace cues will guide you on race day and let you know when to hold back and when to push.
Hydrate All Week
We hear it time and time again, but drinking enough water and topping up on electrolytes is SO important, especially when racing in the heat. If you're aware that your race will be during a particular hot week, you should look to increase your water and electrolyte intake not just on the day of the race, but for the entire week before.
If you haven't considered it before, a hydration vest will allow you to carry extra water and electrolytes easily on race day and will mean that you don't have to be completely reliant on aid stations.
Dehydration can increase muscle cramping and can also be very dangerous. Check out our guide to electrolytes and hydration for more guidance.
Tip: Whilst it's critical to stay hydrated, it's important not to overcompensate. Drinking excessive water can dilute your sodium levels (which can hinder muscle function), and overloading on electrolytes can upset your stomach. Sip steadily and base fluid consumption on your activity and sweat rate.
Hyper Hydration
For races taking place in extreme heat, Amy from The Running Dietitian recommends considering hyper hydration. Hyper hydration means intentionally increasing fluid intake the day before your race to create a buffer against the fluid and electrolyte losses you’ll face on course. A practical guideline is to add 16-32 oz of extra fluids along with 500–2,000 mg of sodium. This helps your body retain the extra fluid, rather than just excreting it, giving you a hydration reserve to start the race better prepared.
Fueling in the Heat
Although hydration should be your top priority when preparing to race in the heat, you should also consider how your fueling strategy may be affected.
Tip: When running in hot conditions, your body burns through glycogen more quickly, so your normal fueling plan may fall short. To avoid bonking, consider increasing the frequency of gels or chews. You can also add an endurance drink (such as Skratch) to boost carb intake while simultaneously covering the higher fluid and sodium needs that come with heat.
Keep Your Body Temperature Under Control
Expect to feel hotter than normal during your race. Your heart rate may be higher than usual as your body tries to regulate in the high temperatures. If you feel particularly hot, grab extra water at aid stations and use it to cool your body.
Coach Ben says: "The areas your body loses the most heat from are your head, feet and backs of your hands. If you have some spare water, pouring it down the backs of your arms and hands can help cool your body temperature."
Choose the Shaded Path
Sometimes, sections of the course can be more shaded than others. If it's possible, try to stick to shaded parts of the course as much as you can.
Consider Your Kit Choices
There's nothing more distracting mid-race than regretting your kit choice. Running kit that felt manageable during training might feel uncomfortable on an especially hot day so here are some factors to consider:
Be mindful about the fabric you choose. Make sure its breathable.
Colours matter too. Avoid dark colours, white reflects more of the sun’s light.
Looser fitting clothing allows for more air flow and sweat evaporation from the skin, whereas tighter clothing can help prevent chafing caused by moisture.
Make a considered decision based on what has worked for you in training. Don't make any drastic changes. The most important thing is that you feel confident and comfortable in what you wear.
Kit Recommendations
Split Shorts: Split shorts are designed for free range of motion and aeration. Runna's split shorts are Made with EcoTech MESH to keep you feeling cool and confident throughout your race.
Singlet/Vest: A sleeveless top helps in the heat by reducing insulation and allowing sweat to evaporate more efficiently. Runna's white race singlet is ideal for hot conditions, designed with EcoTech VENT technology, the 3D vent mesh structure is built to keep your core cool.
Sunglasses: If you're comfortable racing in running sunglasses, they will reduce strain on the eyes and can make the heat feel psychologically less intense.
Technical Socks: The small but mighty addition to your kit when racing in the heat. Technical running socks are ultra lightweight and encourage evaporative cooling, so will make all the difference.
Running Shoes to Wear in the Heat
On race day, opting for a lightweight shoe can help in hot conditions. Modern, carbon-plated super shoes are particularly effective because of their lightweight, stripped-back design and breathable uppers.
Most models use engineered mesh that allows air to flow freely and sweat to evaporate. The minimal material used can help reduce heat and moisture build-up, while the responsive foam and carbon plate used in the shoe encourages forward momentum and improves energy return, which is advantageous in all conditions.
The most important thing is to not try a brand new pair of running shoes on race day. Make sure you've tested them out in training and that they're comfortable.
The Bottom Line
The bottom line is: it's HARD racing in the heat! Your body will be focusing on keeping you cool, so your paces may not be as fast as you expect them to be. Don’t let it knock your confidence or make you doubt your fitness. You’re not unfit or unprepared, you’re simply adapting to the conditions. Remember, every runner faces the same challenge in hot weather. Focus on running smart, staying cool, and enjoying the race.