Phoenix Walks: Is Asphalt Cooking Summer Gels?

By Franklin Everett Shaw

April 6, 2026

Imagine reaching for that energy gel halfway through a scorching run in Phoenix, Arizona. You tear it open, expecting a burst of sugary energy, only to find a lukewarm, semi-liquified mess oozing out. That’s the reality of fueling in the desert heat. It’s not just about hydration; it’s about how the extreme temperatures affect the very fuel you’re relying on.

The Phoenix sun is relentless. Asphalt temperatures can easily soar above 150°F (65°C) during the summer months. This extreme heat doesn’t just make running uncomfortable; it fundamentally alters the composition and effectiveness of energy gels. We need to understand how to mitigate these effects to avoid performance setbacks and, more importantly, GI distress.

Let’s talk storage. Stashing your gels in your car, even for a short period, is a recipe for disaster. The inside of a car in Phoenix can quickly become an oven. Instead, consider these options:

Insulated Pouches: Invest in a small, insulated pouch or cooler bag. These can be surprisingly effective at maintaining a lower temperature, especially when combined with a small ice pack. Think of it as a mini-fridge for your gels.
Hydration Pack Placement: If you’re using a hydration pack, place your gels in an internal pocket, close to the water reservoir. The water will act as a coolant, helping to keep the gels cooler than if they were exposed to direct sunlight.
Pre-Cooling: Before heading out, store your gels in the refrigerator or freezer for a short period. This will give them a head start in staying cool. Don’t freeze them solid, though, as this can also alter their consistency.
Avoid Direct Sunlight: This seems obvious, but it’s worth repeating. Never leave your gels exposed to direct sunlight, even for a few minutes. The dark packaging can absorb heat quickly, accelerating the degradation process.

I conducted a small, admittedly unscientific, experiment to illustrate the point. I placed three identical energy gels in different conditions for one hour on a typical Phoenix summer afternoon (ambient temperature 110°F/43°C):

Asphalt Exposure: Directly on the asphalt.
Car Interior: Inside a parked car.
Insulated Pouch: Inside an insulated pouch with a small ice pack.

The results were telling. The gel exposed to the asphalt was almost completely liquefied, with a noticeable change in color and smell. The gel in the car was also significantly softer and warmer than the control. The gel in the insulated pouch remained relatively cool and maintained its original consistency.

The consistency change is crucial. Many energy gels rely on a specific viscosity for optimal absorption. When the gel becomes too liquid, it can be absorbed too quickly, leading to a sugar rush followed by a crash. Conversely, if the gel becomes too thick (which can happen if it’s repeatedly heated and cooled), it can be difficult to swallow and digest, potentially causing stomach upset.

Recognizing a heat-compromised gel is essential. Here are some warning signs:

Change in Consistency: If the gel is significantly more liquid or thicker than usual, it’s likely been affected by the heat.
Change in Color: Any noticeable change in color, especially darkening or browning, is a red flag.
Unusual Odor: A sour or fermented smell indicates that the gel may have spoiled.
Bloated Packaging: If the packaging is bloated or bulging, it’s a sign that the gel has fermented and produced gas.

If you notice any of these signs, do not consume the gel. It’s better to be safe than sorry. GI distress during a workout can be debilitating, especially in the Phoenix heat.

Now, let’s talk about specific gel types. Some gels are more heat-resistant than others. Gels with a higher water content tend to be more susceptible to liquefaction. Gels with a thicker, more viscous consistency may hold up better in the heat. Experiment with different brands and types to see which ones work best for you.

Consider these practical tips for your Phoenix workouts:

Early Morning or Late Evening Runs: Avoid the hottest part of the day. Run early in the morning or late in the evening when temperatures are cooler.
Shorter Distances: Adjust your workout distance and intensity based on the heat. Don’t try to push yourself too hard in extreme conditions.
Hydration is Key: Drink plenty of water before, during, and after your workout. Dehydration can exacerbate the effects of heat-compromised gels.
Listen to Your Body: Pay attention to how you’re feeling. If you start to experience any signs of heat exhaustion or GI distress, stop and seek medical attention.

One common mistake I see is runners relying solely on gels for fuel during long runs. In Phoenix, this is particularly risky. The heat can make it difficult to tolerate gels, even if they’re properly stored. Consider incorporating other fuel sources, such as chews or real food, that may be easier to digest in the heat.

Another pitfall is neglecting electrolyte replacement. Sweating profusely in the Phoenix heat depletes your body of essential electrolytes, which can contribute to GI distress. Choose gels that contain electrolytes or supplement with electrolyte drinks or tablets.

Finally, don’t be afraid to experiment. What works for one person may not work for another. Try different gel storage methods, gel types, and fueling strategies to find what works best for you in the Phoenix heat. Keep a log of your experiences to track what works and what doesn’t.

Living and training in Phoenix presents unique challenges. But with a little planning and preparation, you can overcome these challenges and continue to enjoy your outdoor workouts. Don’t let the heat defeat you. Adapt, adjust, and conquer. Remember, a well-fueled and hydrated athlete is a happy athlete, even in the scorching Arizona sun.