As winter fades away and the vibrant hues of spring emerge, runners eagerly embrace the warmer temperatures and longer days. However, with the rising mercury comes a new set of challenges for those hitting the pavement or trails.  As temperature increases, effort increases and paces slow down.   Running in hot weather demands careful consideration of various factors to ensure both performance and safety. From choosing the right time of day, to hydrating effectively, dressing appropriately, and understanding the impact of humidity and alcohol consumption. Here’s everything you need to know to thrive in the heat.

Also, running in heat may affect your end goal performance, if you are not diligent.  Hotter weather creates a higher heart rate.  So a workout that should be done at medium effort, could elevate to a hard workout in the heat, if pace is not adjusted.  And an easy workout could be a harder effort without you even knowing, due to rising temperatures.  Compounding things, these efforts could affect recovery times and therefore future performances.

Transitioning to Hot Weather Running

The transition from cooler to warmer temperatures requires a shift in approach for runners. As the days become hotter, it’s crucial to adapt your routine accordingly. Gradually acclimating your body to the rising temperatures is essential to prevent overheating while continuing to improve performance. Start by incorporating shorter runs in the heat and gradually increase both distance and intensity as your body adjusts.

Best Time of Day to Run

Choosing the optimal time of day to run can make a significant difference in your hot weather training. Early mornings or late evenings are generally the best times to lace up your running shoes during hot weather. These times offer cooler temperatures, reduced UV exposure, and lower humidity levels, minimizing the risk of heat-related illnesses and enhancing overall comfort.

Running in the early morning allows you to take advantage of cooler temperatures before the sun’s intensity peaks. Similarly, evening runs offer relief from the day’s heat while still providing ample daylight for visibility. Avoid midday runs when the sun is at its highest and temperatures soar, increasing the risk of dehydration and heat exhaustion.

Dressing for Hot Weather

When it comes to dressing for hot weather running, lightweight, moisture-wicking fabrics are your best friend. Opt for loose-fitting clothing in light colors to reflect the sun’s rays and promote airflow, keeping you cooler and more comfortable throughout your run. Breathable materials such as polyester blends or technical fabrics help wick away sweat and prevent overheating.

Choosing the right footwear is equally important. Look for running shoes with breathable uppers and ample cushioning to provide comfort and support while allowing for ventilation. Additionally, consider wearing moisture-wicking socks to keep your feet dry and blister-free, especially on longer runs in hot conditions.

Hydration Strategies

Staying properly hydrated is crucial for maintaining performance and preventing heat-related illnesses during hot weather runs. Begin hydrating well before your run and continue to drink fluids throughout your workout to replenish lost fluids and electrolytes. Water is essential, but for longer runs or intense workouts, consider incorporating sports drinks or electrolyte supplements to replace sodium and potassium lost through sweat.

Monitor your hydration status by paying attention to thirst cues and urine color. Aim to drink enough fluids to maintain pale yellow urine, indicating adequate hydration. Remember that individual fluid needs vary based on factors such as sweat rate, intensity of exercise, and environmental conditions, so listen to your body and adjust accordingly.

Impact of Alcohol on Hot Weather Running

While a post-run beer may seem appealing, consuming alcohol before or during hot weather running can have detrimental effects on performance and hydration. Alcohol acts as a diuretic, increasing urine production and promoting fluid loss, which can exacerbate dehydration during exercise. Additionally, alcohol impairs thermoregulation and reduces the body’s ability to dissipate heat, raising the risk of heat-related illnesses such as heat exhaustion or heat stroke.

If you choose to indulge in alcoholic beverages, do so in moderation and be mindful of timing in relation to your runs. Avoid excess alcohol consumption in the hours leading up to a run, and prioritize hydration before and after drinking to mitigate its effects on your performance and safety.

Effect of Humidity on Running

Humidity can significantly impact your hot weather runs by limiting the body’s ability to cool itself through sweat evaporation. High humidity levels make it harder for sweat to evaporate from the skin, leading to increased perceived exertion, decreased performance, and elevated risk of heat-related illnesses.

When running in humid conditions, take extra precautions to stay cool and hydrated. Wear lightweight, breathable clothing, and consider running routes with shade or access to water fountains for additional relief. Pay attention to your body’s cues, and if you start to feel overheated or fatigued, take breaks as needed and seek shelter from the heat.

Getting Acclimated to Hot Weather

Acclimating your body to hot weather running is essential for improving performance and reducing the risk of heat-related illnesses.   You can condition yourself to get better in dealing with heat.  A slow and gradual introduction to hotter weather will see physiological adjustments and you will see an increase in performance at those temperatures.  Be patient with the process, and listen to your body’s feedback to avoid pushing yourself too hard too soon.

FYI Women acclimate to hotter temperatures better than men.  

Choosing the Right Surfaces

The surface you choose to run on can also impact your experience in hot weather.  Black asphalt of the roads is the hottest surface for warm weather running.   Concrete, although cooler. creates ambient heat also.  Look for tree lined trails of dirt or gravel or map out shaded routes.  Running smart can also help lower the ambient temperature and provide relief from the sun’s rays.

Sunscreen and Protection

Don’t forget to protect your skin from the sun’s harmful rays when running in hot weather. Apply a broad-spectrum sunscreen with an SPF of 30 or higher to exposed skin before heading out for your run, and reapply as needed, especially if sweating profusely or spending extended periods outdoors. Slather on that SPF like it’s your job, paying extra attention to those oft-forgotten areas like your ears, neck, and scalp. Because nothing ruins a run faster than a sunburn that makes you look like a lobster who took a wrong turn at the beach. Wearing a lightweight, breathable hat and UV-protective sunglasses can also help shield your face and eyes from sun damage.

Heat Index and Adjusting Pace

Heat index, which combines air temperature and relative humidity to determine how hot it feels, can be a useful tool for assessing the safety of outdoor activities, including running. As heat index values rise, so does the risk of heat-related illnesses, prompting the need for adjustments to pace and intensity.

Consulting a heat index chart or calculator can help you determine how to modify your pace based on current environmental conditions. There are many available on the internet.  Some are simple with just heat and dew point/humidity while others take into account factors like temperature, humidity, body weight, fitness, distance and even wind speed to help you adjust your pace for optimal hot weather running.  As a general rule, slow down and listen to your body when running in hot weather to avoid overheating and dehydration. Consider shortening your runs or moving them indoors to air-conditioned spaces if heat index values exceed safe thresholds for outdoor exercise.

A loose way of figuring out your pacing for a run is time vs temperature.  So with approximately 60 degrees being the optimal running temperature we make adjustments for every degree above 60.  So we are looking at about 1-2.5 seconds per mile adjustment per 1 degree increase..  For smaller, faster runners 1 sec per mile per and for less swift and larger runners up to 2.5 seconds per mile adjustment.  So the average runner running in 85 degree weather should slow down 40-50 seconds per mile.  So if your training pace is 8:20 then 9-9:10 should be your adjustment.   Of course, if you are acclimated you may be able to adjust your pace.   But, always consult your perceived effort to guide you.  

In conclusion, running in hot weather requires careful planning and preparation to ensure both performance and safety. By choosing the right time of day, dressing appropriately, staying hydrated, and paying attention to environmental factors such as humidity and heat index, you can optimize your hot weather training and continue to enjoy the benefits of running year-round. Remember to listen to your body, respect the heat, and make adjustments as needed to stay safe and healthy. 

Now go forth and make that pavement or trail sizzle!

Here is a simple heat calculator from runners connect    https://runnersconnect.net/training/tools/temperature-calculator/