Hydration
Our bodies are always losing water. We can drink after the loss, and play catch-up, or we can begin a ride by drinking before we start and build a reserve. The harsher the environment (heat) and the longer the ride, the more we need to have a plan for hydration.
As sports and activities go, riding in high temperatures for many hours at a time is very much an extreme activity. It requires more extreme measures. This is very different than someone who plays soccer for an hour or two and sweats a little. Being subjected to multi day temperatures of 110F or more and winds of 60mph for hours on end qualifies as an extreme activity. You need a plan.
Do you have a plan?
Drink frequently. The goal is not to gorge on water, but to replace water lost by sweat and breath.
Instead of playing catch-up with hydration, begin hydrating lightly a day or two before extended touring in hot climates, and increase the use of salty snacks.
Then, two hours or so before departure, drink from 12 to 24 oz. of water. This allows enough time for the body to fill its need for water and to dump the excess as urine. Fifteen to twenty minutes before the start, drink another 10-16 oz. This will be used to fuel initial sweat production, without dipping into the body's hydration stores.
This sequenced intake provides a base that your system can access for sustained sweating as well as system functioning. From then on, drink lightly but frequently.
The higher the rate of sweat, the more electrolytes you need. This can either be from a sport drink, a banana, or a very convenient electrolyte capsule. The benefit of an electrolyte capsule is that it travels well, and offers a preset dosage of electrolytes.
So how much can I gulp down?
Drinking smaller amounts of water often is best, ie. 8 to 12 ounces. On a motorcycle, this involves having some sort of onboard water supply that allows you to drink on the fly.
In hot weather riding, drinking large amounts every 2 hrs is nowhere near as good as drinking smaller amounts at more frequent intervals.
Gulping down significant amounts of water may actually be counter productive since there is a limit as to how much water our stomach can process at one time.
The typical maximum rate of absorption for liquid is between 25 to 30 ounces per hour.
With large gulps, much of the water may end up sitting in our stomach, as opposed to being rapidly absorbed and put to use. Water sitting in our stomach only makes us feel bloated.
Gulping larger amounts of water also implies waiting for longer intervals between drinks. During this time, our system is subjected to a yo-yo effect as we replenish and then deplete its resources with our electrolyte levels swinging from significant concentration to significant dilution.
This is because heavy and rapid water intake has a direct and quick effect on our blood volume, momentarily diluting our blood’s concentration. So we spend the day going from concentrated blood to diluted blood, back and forth, which is not ideal.
It is similar to long discharge intervals between recharges for an automotive battery. Deep discharge rates are not good for the battery. The ideal situation is to hook the battery up to an automatic charger that will give it what it needs in small doses over time. The same reasoning applies here.
How serious is this need to ensure hydration?
Consider that during high speed, hot weather riding, you can lose up to 50 ounces of water per hour or more, and yet you can only absorb a maximum of approximately 30 ounces per hour. Assuming that you are very dilligent and hydrating maximally, after 5 hours of riding in intense heat you will still be in water deficit by 100 ounces!
This underscores the importance of getting a head start by beginning to hydrate before the ride begins and then continue by drinking often. Because there is a limit to how much water we can absorb over a one hour period, you cannot make up for forgotten drink by drinking more. This is where having a plan and sticking to it takes on more meaning.
Drink after a ride, even if you find yourself in a nice air conditioned room. You may no longer need water to allow for sweating, but you want to replace the water lost since your last hydration. You also want to begin building reserves for tomorrow’s ride. Remember the plan.
Eating some salty food or snacks (unless you have high blood pressure) will be good on 2 levels. It will increase your thirst level as well as helping your body retain more of the water by replenishing your sodium (electrolyte) levels.
note: Caffeine and alcohol are diuretics. They will increase water loss through urination. Alcohol also tends to pull water from brain cells and other organs, dehydrating them. Something to consider when hydration is critical.
Summary: If you expect to be sweating for hours on end, especially on a multi day hot weather ride, drink before the need arises in order to build up reserves and take electrolytes in order to process this water optimally.