Optimizing Your Training for Hot Weather Running

Running during the summer season offers excitement, thanks to the extended daylight, the kickoff of autumn race preparations, and the relief of shedding those multiple layers during your runs. Nevertheless, summer running presents its unique set of hurdles, primarily the sweltering heat and high humidity levels, which can make running feel exceptionally taxing.

Remember, you’re not alone in finding summer running demanding, and it doesn’t indicate a loss of fitness on your part. Running in hot weather poses greater physiological challenges. This article will explore the reasons behind the grueling nature of hot-weather running and provide practical advice on how to enhance your summer running experience.

Why Does Running in High Temperatures Feel So Challenging?

Endurance in the heat isn’t merely a test of mental fortitude. In reality, elevated temperatures, humidity, and direct sun exposure all have detrimental effects on your aerobic performance.

Firstly, heat causes a decrease in maximum aerobic capacity. Your heart rate escalates while stroke volume decreases, resulting in reduced overall cardiac output despite the elevated heart rate. Consequently, your brain and muscles receive less blood flow as your body redirects more to the skin for cooling. These physiological shifts are exacerbated by increased sweat rates, leading to fluid loss and a reduction in blood volume. This, in turn, forces your heart to work harder to supply oxygen-rich blood to your active muscles.

Metabolically, running in the heat relies more on carbohydrates. This heightened reliance on glycolysis for energy production generates additional metabolites, such as hydrogen ions, which hasten the onset of fatigue.

Furthermore, your nervous system plays a role in regulating your effort. When running in hot conditions, your muscles transmit more inhibitory signals to your brain, potentially leading to reduced muscle contraction as a protective response.

Your perceived effort level, as measured by Rate of Perceived Exertion (RPE), also skyrockets. Whether you gauge your training intensity through heart rate or RPE, you’ll observe that the same running paces feel more arduous and correspond to higher heart rates in hot conditions.

All these physiological alterations are necessitated by the body’s need to regulate its temperature.

 

The Advantages of Running in Hot Weather

You may have come across the saying that “personal records in the fall are forged during the summer.” It implies that enduring the most challenging summer conditions is essential for your October or November race preparation. During this period, your body adapts to the heat and humidity, leading to significant changes in hemoglobin mass and blood volume. When you reach your fall race, and the temperature cools, you can reap performance benefits from the increased hemoglobin and blood volume, all without the summer heat stress.

Heat acclimation has become a hot topic in the world of endurance sports. Unless you are specifically gearing up for a demanding race in hot conditions, there’s no need for special measures. Just by training outdoors during the summer, your body naturally adjusts to the heightened heat stress.

A 2019 study featured in Frontiers in Physiology investigated the adaptations of cyclists who consistently engaged in short, moderate-intensity sessions in the heat. These cyclists displayed improved power outputs at lactate threshold and during time trials when compared to the control group. Additionally, the heat-trained cyclists experienced increases in plasma volume and hemoglobin mass, which could explain their performance enhancements.

It’s worth noting that these changes resulted from relatively brief and manageable efforts in hot conditions. The cyclists in the 2019 study did not subject themselves to their most strenuous or lengthy sessions in extreme heat. Pushing for every training session in scorching weather might lead to overtraining or an elevated risk of heat-related stress for athletes.

 

The Effects Of Dehydration When Running In The Heat

Maintaining proper hydration levels is a crucial factor in your ability to endure and perform well in hot weather during your runs. If you’re struggling significantly with running in the heat, even after reducing your pace, it might be essential to give more attention to your hydration status.

Hydration is a constant concern for runners, but it becomes even more challenging during summer training. The heat tends to elevate sweat rates, leading to increased fluid loss through perspiration compared to other seasons. Consequently, your hydration requirements are heightened in the summer.

During the summer, even slight degrees of dehydration can accumulate over time. You might finish one session slightly dehydrated, fully rehydrate afterward, but start the next session still slightly dehydrated, gradually worsening as you continue.

The significance of dehydration lies in its detrimental impact on your body’s core temperature regulation. Dehydration, even at levels as low as approximately 2%, impairs your ability to dissipate heat effectively. It results in decreased blood volume and increased plasma osmolarity, hindering efficient sweat production for cooling. This elevated core temperature prompts your body to conservatively lower its exercise capacity.

While heat naturally leads to a decline in performance, dehydration exacerbates this decline. Just a 2% loss of body weight due to sweating can reduce your time to exhaustion. When combined with the reduced cardiac output experienced in hot conditions, your running performance can suffer significantly.

It’s essential to understand that training while dehydrated won’t enhance your ability to adapt to the heat. Dehydration offers no benefits to your training; it only leads to decreased performance and an increased risk of heat-related stress.

Furthermore, dehydration can make you more susceptible to gastrointestinal distress. It slows down your gastric emptying rate by as much as 20-25%, causing fuel and fluids to linger in your stomach and gastrointestinal tract longer than necessary. If you sense fluid sloshing in your stomach on a hot day, it may indicate dehydration, signaling the need to continue drinking fluids.

 

Staying Hydrated for Running in Hot Weather

The importance of staying adequately hydrated cannot be overstated when running in summery conditions. Hydration should be a constant consideration, encompassing the periods before, during, and after your runs, as well as throughout the entire day.

Before embarking on your run, pre-exercise hydration takes precedence. If you’ve noticed that you struggle to consume enough fluids during your runs, experience discomfort from the outset, or have difficulty coping with the heat, it’s possible that you’re commencing your runs in a dehydrated state. While individual hydration requirements may vary among runners, a general guideline is to consume 12-16 ounces of water or a sports drink within the two hours leading up to your run.

Hydration needs during your run also vary widely. Some runners sweat lightly, while others are profuse sweaters. A 2017 review in Sports Medicine highlights the influence of individual factors such as age, gender, heat acclimation, exercise duration, exercise intensity, and even medication use on sweat rates. Sweat rates can differ significantly, ranging from 0.5 to 2.5 liters per hour, representing a five-fold variation.

To determine your specific sweat rate, you can undertake a sweat test. Websites like Featherstone Nutrition provide calculators and instructions for conducting this test. For reliable results, perform the sweat test under summer conditions.

It’s important to note that, even after conducting a sweat test, there may be variability in sweat loss from one session to another. The sweat test aids in customizing your hydration needs, but you should still make adjustments based on your thirst during each run. Once you ascertain your sweat rate, a general goal is to consume approximately one-half to two-thirds of your losses. For example, if you lose 20 ounces of sweat per hour, your hydration target would be around 10-15 ounces per hour.

Lastly, post-run hydration is vital. Consuming 8-16 ounces of a sports drink or water immediately after your run is beneficial. Subsequently, focus on maintaining proper hydration throughout the remainder of the day.

 

Adapting to Running in Hot Weather

You can regulate your body temperature by making behavioral adjustments, which can help prevent reaching a point during your run where the heat becomes unbearable.

1. Opt for Light-Colored Attire:
Dark-colored clothing tends to absorb heat, which is less than ideal for a summer run. Instead, choose light-colored hats, shirts, and sports bras to keep yourself cooler on hot days. Some runners even prefer white hydration vests for their summer long runs.

2. Time Your Runs Wisely:
Solar radiation can make you feel warm even in relatively mild temperatures. The sun’s direct rays can raise your skin temperature. Whenever possible, schedule your runs early in the day, late in the evening, or along shaded routes. Minimizing direct sun exposure can help you feel more comfortable during your run.

3. Carry Fluids:
As previously mentioned, dehydration increases your susceptibility to heat stress. While you may be able to run for an hour in winter without needing to drink, summer runs often call for hydration. Consider carrying sports drinks or water with you. If using plain water, think about supplementing with salt tablets to replace lost sodium from sweating. A general guideline is to bring fluids on any run lasting longer than 50-60 minutes. Certain individuals, such as pregnant runners, those on medications like anticholinergics or antidepressants, and those with specific medical conditions, may need fluids on shorter runs. Choose handheld water bottles, hydration belts, or hydration vests based on your comfort and the duration of your run.

4. Employ Cooling Techniques, Especially During Extended or Intense Sessions:
Cooling techniques targeting areas like your head, neck, and core can aid in regulating your body temperature without hindering heat adaptation. A 2015 meta-analysis revealed that pre-cooling (consuming cold fluids beforehand, using cold towels) and percooling (using ice during the run, pouring cold water on yourself) led to an overall 6.7% performance improvement in hot conditions. These techniques are particularly advantageous during long runs, challenging workouts, and races in the heat.

5. Focus on Effort, Not Pace:
Due to the factors mentioned above, you may find that you run at a slower pace while maintaining the same Rate of Perceived Exertion (RPE) or heart rate in hot weather. It’s crucial not to push for faster paces during the summer; instead, use effort as your guide for both easy runs and strenuous workouts. You might even need to scale back the intensity of your hard workouts. This article provides guidance on adjusting workouts to accommodate the heat and humidity.

 

Is Running in Hot Weather Potentially Hazardous?

Running in hot weather can indeed become dangerous, and there isn’t a precise threshold to define it. Several factors come into play, including your fitness level, workout intensity, ambient temperature, humidity, and sun exposure, all contributing to the risk of heat-related illnesses.

Recognizable signs and symptoms of heat-related illnesses encompass:

– Nausea and vomiting
– Confusion and altered mental state
– Elevated heart rate
– Low blood pressure
– Lightheadedness and dizziness
– Uncontrollable thirst
– Muscle twitching
– Fainting
– Headache
– Hot skin and an elevated body temperature

Should you encounter any of these symptoms during your run, it’s imperative to cease running immediately. Depending on the severity of your symptoms, you may need to seek additional medical attention, especially if you lose consciousness.

When running with a dog or a child in a jogging stroller, it’s essential to bear in mind that they have lower heat tolerance compared to adults. The same caution applies if you choose to run with your pet or child, particularly on hot days. Safety should always be a priority in such situations.

 

Final Words – How To Best Adjust Your Training For Running In The Heat

In conclusion, summer running brings its own set of challenges, with scorching heat and high humidity making it a demanding endeavor. However, understanding the physiological factors at play and adopting smart strategies can help you navigate these hurdles safely and effectively.

Running in the heat presents unique physiological challenges, including reduced aerobic capacity, increased reliance on carbohydrates, and heightened perception of effort. These changes are primarily driven by the body’s need to regulate temperature in hot conditions.

On the positive side, training in the heat can lead to beneficial adaptations, enhancing your performance in future races. Acclimating to the heat gradually, maintaining proper hydration, and implementing cooling techniques are key components of successful summer running.

Dehydration in hot weather can exacerbate performance decline and increase the risk of heat stress. Therefore, paying close attention to your hydration needs before, during, and after runs is crucial.

Adjusting your running attire, choosing optimal run times, carrying fluids, practicing cooling methods, and focusing on effort rather than pace are effective ways to enhance your summer running experience while minimizing potential risks.

Lastly, it’s vital to recognize the signs of heat-related illnesses, such as nausea, confusion, high heart rate, and lightheadedness, and take immediate action if you experience these symptoms during a run. Additionally, exercise caution when running with pets or children in hot weather, as they are more susceptible to heat-related issues.

By staying informed and implementing prudent strategies, you can enjoy your summer runs safely and make the most of this challenging but rewarding season.