Summer is in full swing and so is the heat. Time to literally get a good sweat on to take advantage of the hot weather so you can shed those extra pounds and up your fitness game. But training in the heat is no fun unless it's in the water. What’s more is the heat presents a lot of ‘challenges’ and, like all challenges, we can rise to meet them or we can allow them to limit and even defeat us. 

Fortunately, we Humans are supremely robust and adaptable. Millions of years of Human Evolution have shaped us to have an innate robustness and unique adaptations which confer several advantages in the heat. Adaptations like having a lot less hair feathers or fur, sweat glands and a single stomach, acid & bile digestive tract instead of a multi-compartment one made for fermentation. 

So while we are uniquely adaptable to the heat, the heat still presents challenges especially in the modern man-made world where the conveniences of air conditioning, relatively sedentary lifestyles and highly processed and easily accessible food have undone our evolutionary adaptations and tolerance to the heat. This presents modern man with these three challenges:

One: Acclimating to the heat

Two: Fueling in the heat

Three: Hydration

Heat Acclimatization:

The first challenge is adapting to the heat itself. This is a very real process and occurs on a cellular and mitochondrial level in response to constant exposure to elevated temperatures and physical activity. The proteins which make up the mitochondrial complex literally refold or remake themselves to be able to be better able to dissipate heat. Normally this is a 2-3 week process of training in the heat and/or exposing yourself to super high temperatures such as sessions in the sauna or steam room. 

During this process you will note that not only is your sweat rate high but also that your concentration of salt in your sweat is very high which is evidenced by salt caking on your skin and clothing.  Once you see the salt staining dissipate you are adapting. You will also conserve sweat on cooler days.

Heat Acclimatization means getting comfortable with the uncomfortable knowing you will be a better and truer version of yourself for doing so. 

Fueling in the Heat:

We are constantly being told we ‘need’ to fuel, and, on the surface, this makes a LOT of sense, after all it takes energy to move and the faster and harder you go the greater the energy demand. 

This modern approach presents a conundrum in the heat. The more calories taken in, the greater the risk of serious and debilitating GI issues. You know, the nausea, gas, bloating and worse. It's just no fun.

And this modern approach has focused on developing various products and strategies to get more calories ‘in’, rather than an approach more aligned with our biology and evolutionary heritage of harnessing our onboard energy. This conventional focus on external calories, a one dimensional approach, leads to a dead end when trying to fuel in the heat. What’s more it has long term implications for both your performance and overall health and vitality.  

How The Wrong Fueling Strategy Can Hurt You

In the case of physical activity in the heat your body is shunting blood from your muscles to your skin to sweat to dissipate the energy/heat generated for physical movement. The hotter the temperatures, the higher the humidity and the greater the effort the more sweat you have to generate to thermoregulate. Under such conditions the body essentially places the digestive tract on ‘sleep’ mode meaning blood flow to the GI tract is minimized. This fact alone compromises your ability to process and assimilate calories beyond simple sugars thus making you susceptible to GI challenges.

Point is you really can’t assimilate anything more than a trickle of simple sugars in the heat. ... .and you shouldn’t try to ‘train’ your gut to tolerate more calories than it can during exercise regardless of the temperatures. Here is why: No matter what the conditions, blood flow to your GI tract is compromised by physical activity and the heat. This is exactly why you don’t do calisthenics when you sit down for an evening meal, any more than you try to eat a meal on the run and why we tend to be hunger suppressed when it's hot and our hunger turns up in the cold.

These are simple physiological responses and physiological facts nobody argues about, yet, somehow in our mis-guided quest to get more calories in, rather than harness the ones we have locked inside us, we have lost the narrative of our natural heritage for one that can be monetized. 

This is where optimizing fat metabolism confers a tactical advantage. . . you simply need a fraction of the calories an athlete who is dependent upon carbohydrates needs to maintain performance under hot conditions. What’s more you won’t bonk, avoid GI issues and prevent damage on a cellular level.  Any significant shift to increase fat oxidation profoundly impacts your external energy needs, the easiest and quickest way to move this needle is by incorporating Vespa, a naturally occurring peptide which is a catalyst to shift your body’s metabolism back to the energy source you are meant to harness for aerobic activity -  fat.

Hydration:

Physical activity in the heat, particularly strenuous activity, creates a critical need to stay on top of Hydration. And while most people know they need to hydrate they do not recognize hydration is much more than drinking water or sports drinks like Gatorade. Here are some key points:

Hydration is dynamic, highly dynamic. The potential for swings in your hydration needs can be huge based upon the different variables of temperature, humidity, activity/sport and the intensity level of your physical activity. 

Once again, your robust native physiology has built in mechanisms to maintain homeostasis, meaning you don’t have to perfect Hydration. The main goal should be to simply focus on replacing  the water and principal electrolytes you lose through sweat, breathing, and urine, and your body will adjust to make up the difference over time using your built in reserves. 

A well conditioned male athlete can lose over a liter of fluid an hour in the heat so it is vitally important to properly hydrate for anything beyond 90 minutes of duration when hot. 

Sodium is the principal electrolyte for extracellular fluid balance including blood and plasma and why Sodium and Chloride are the principal electrolytes lost in sweat. Precisely why sweat tastes salty. Maintaining this electrolyte balance through replacing what is lost via sweat and urine is crucial not only for performance but health.

While your body has reservoirs of Sodium in the Liver and skeletal tissues to buffer some water intake, for optimal performance Sodium supplementation is vital. Recent trials have shown that well-conditioned endurance athletes can consume up to 2000 mg (2 grams) of Sodium with approximately 50 ounces of water over a 60-90 minute period of relatively intense exercise in the heat!

While this is an upper limit, most male athletes will require between 700 to 1500 mg of Sodium per hour to sustain performance level physical activity in the heat, with females requiring 500-1200 mg per hour. These are ballpark numbers which give you an idea of where to start. 

If you can simply focus on replacing water and Sodium you can avoid cellular dehydration and easily rehydrate after your activity. This will minimize GI issues and help minimize caloric needs and optimize recovery. 

If you have the opportunity or logistics to cool yourself off, take full advantage of them. Cold Water, Ice, ice cold drinks, including crushed ice and slushies all will help in thermoregulation. Cooling your head and core down have profound impacts on the mental signaling that regulates your output in the heat.

Use these 3 strategies and you will find yourself avoiding the bonk, GI issues and have a secret weapon to dominate in the heat this summer.