Warm and Cool: Core Temperature Benefits
By now you should be well versed in the benefits of staying hydrated, for both life and endurance performance. Smart and proper hydration forms the bedrock of a smart strategy to your fueling, nutrition and hydration strategy, but what about the temperature of the fluids you take in? Are there scenarios in which we take the next step and implement specific types of drinks and different temperatures to give us that boost of energy and alertness? Actually, there is indeed and the good news is that it doesn't need to be complex or difficult to implement.
There are two key scenarios in which you should really consider the temperature of the fluids that you take in. Before we dive into these it's important to realize that throughout the course of your day, there is no grand parameter around the temperature of your hydration. If you like ice water to sip on throughout the day or if hot tea is your drink of choice, both are effective for supporting your hydration status. Where temperature does become interesting, and a performance tool, is in the regulation of energy management throughout the day, as well as endurance performance in hot and humid conditions.
Let's discuss both scenarios:
Warming your core: I am sure that you have felt those afternoon slumps. Early in the day you have an active mind and productivity is high, but hitting the middle of the afternoon is greeted with fatigue, sleepiness and a craving for caffeine or food. Most of us experience this and there is a very real physiological consideration in why it happens. Our body falls into a natural circadian rhythm throughout each 24 hour period, one which you are most familiar with as you get sleepy as night falls. When you do sleep at night your body falls into a state of rejuvenation and repair, with systems slowing down, and an accompanying drop in our core temperature. We feel this if we ever get woken from our sleep unexpectedly, and I am sure you would agree you don't feel at your most sparky when that happens. Well, a similar scenario occurs, albeit to a smaller degree, in the middle of the afternoon. The body's natural clock will slow down and there will be an associated drop in core temperature. This elicits a feeling of sleepiness and/or hunger. It is at this point that many of us will grab for the sugary energy drink, but this is not what the body is craving. Instead, give your system the rev-up that is desires by drinking a warm beverage. Optimal is some form of non-caffeinated tea, so as not to disrupt that evening sleep. The warm fluids will help to raise your core temperature and alert the system. Before you know it, you will be in for another few hours of productivity and you haven't chosen the poor choice of an energy drink.
Cooling your core: Of course, we don't always want to raise our core temperature. In fact, if you are competing or training in a hot or humid environment, a rising core temperature can be one of the great performance limiters out there. A great example is the extreme case of the Hawaii Ironman in which athletes swim 2.4 miles, ride 112 miles then run a 26.2 marathon in conditions that are very hot and humid. The athletes obviously need to be very fit, be able to take in enough calories and hydration to fuel the effort, but also prevent the core temperature from rising too high. These three areas are the performance limiters in a crazy event like that. Now, you are not likely aiming to endure 140.6 miles in the Hawaii heat, but you might be going for a long run or bike ride in which you want to feel your best throughout the adventure. Keeping your core temperature down is a great performance help.
Interestingly, most athletes aim to do this by pouring water on their head or shoulders, but the body is most effective at cooling from the inside out. In other words, the biggest aim would be to cool the body with the fluid you ingest. It has been repeatedly shown that very cold liquids or slushy type beverages are vastly superior for core cooling. Consistent hydration with ice cold beverages is of great advantage over room temperature. You might ask how to take in cold beverages when you are out on a bike ride or run. Well, there are a few tricks. I often endorse athletes freezing their bottles of hydration the night prior to their ride so that they remain cool for a long period of time, even as they melt, keeping the cooling effect optimal. If you are in particularly harsh conditions, you can consider wrapping these bottles in aluminum foil. This simple insulating trick is effective in keeping the fluids cool and you don't need to strip the foil before placing the bottle in the bottle-cage. Of course, you can also take the best step and use a CamelBak insulated bottle, then you have a clean, tidy and easy cool delivery system without any of the hassle.
Until next time, keep the core temperature up to give you energy, and keep it cool for prolonged energy! Get specific with your hydration, but keep it simple.