Hydration – Pay attention to your Thirst!
Our thirst gives us important cues on hydration by just listening to our body.
Why do we sweat?
Sweat keeps us cool and blood vessels open up so that the heat we produce can radiate off.
Our bodies consist of 60-75% water (more muscles = more water) accompanied with minerals, like sodium, potassium, and chloride. As we sweat (made up of 90% of electrolytes) and water from the sweat evaporates, it takes heat with it and what is left behind is the salt that came out of the skin (the white marks on your jersey). Even though all electrolytes are important to our body’s function and performance, sodium is the most important one. Read More ... There is anywhere from 400 mg to 1200 mg of sodium in a liter of sweat. Imagine for a moment you replenish sweat with water only (and not the sodium lost in sweat), you are not getting the nutrients your body needs for best performance. A decrease in our body’s sodium concentration, also known as hyponatremia, can result into symptoms like headache, confusion, fatigue, nausea to name a few. Maintaining sodium and fluid balance therefore is imperative. A simple rule is to start with a drink containing 300 to 400 mg of sodium per 16 ounces to make up for your losses. If you find that your body requires more sodium, an electrolyte supplement may be necessary. Heat, particularly when coupled with humid conditions, can cause our body to lose its ability to cool itself effectively as particles on our skin meet warm particles in the air. With gains in fitness also comes an increase in sweat rate because the body can generate more energy and thus heat. Another adaptation to increases in fitness is that our body responds to the stimulus of exercise by sweating sooner & can even release less sodium per liter of fluid lots. In short, our perspiration mechanism becomes more efficient as we become more fit.
Reasons to Hydrate:
- To improve performance by maintaining fluid and electrolyte balance in the body.
- To help dissipation of heat from working muscles.
- To support detoxification while bringing good nutrients into cells.
- To keep joints and muscles lubricated and moving.
- To stimulate mental precision for training and race day.
- To keep blood pressure in normal range. As we dehydrate the blood thickens, forcing the heart to work harder for a given effort.
- To promote healthy digestive processes.
It is important to how fluid is transported into our bloodstream and, eventually, into the cells. In short, water is transferred across the wall of the small intestine passively through a process called osmosis. This process is made more efficient when the fluid contains a small amount of sodium and glucose. Osmosis is the movement of a particular fluid from an area of low concentration to an area of high concentration across a semi-permeable membrane (IE the wall of the small intestine). Therefore, consuming a fluid having some salt and sugar is the fastest, most efficient way to replenish the fluid stores in the body. While drinking water alone is fine if you’re having dinner at home, drinking water alone during exercise is not fine if you’re trying to rehydrate when you’re sweating.
How much hydration?
One of the questions we get quite often is: “How do you know how much and what to drink?” The first rule: Listen to your thirst to regulate how much you drink. Keep in mind though that workout duration, intensity, and temperature have an influence on your intake. For shorter, lower intensity efforts in moderate temperatures plain water is all you need, as losing some of your body’s water content during shorter durations and cooler temperatures isn’t likely to cause any problems. For longer and/or harder intensity efforts, especially in high temperatures, where water and sodium loss can be very high (3-5+% of your body weight in water), consume a similar concentration of sodium as contained your actual sweat. Unfortunately, everyone’s sweat is different. Some people lose a little bit of sodium in their sweat (400-700 mg Na/L) while others can lose much more (1000-1500 mg Na/L). Realize that some salt in the range of 600-800 mg of sodium per liter of water is better than just plain water. The second rule: If you are unsure about your actual sodium sweat (don’t or can’t get it measured in a lab), guesstimate your sodium and salt intake by weighing yourself before and after exercise. If your body weight is significantly under its initial weight (>3% of body weight loss), you are drinking to thirst, and you have sufficient access to water and sodium during the workout, then you likely need more sodium to better regulate your thirst mechanism in order to replace the sodium and water you lose during exercise. In theory, the best thing to drink when you’re sweating is your own sweat. But for one, it is unpractical and more so, it tastes unpleasant. If you don’t want a bunch of excessive ingredients (or your own sweat) give your exercise hydration mix a try.
How much is too much? As much as it is important to consume electrolytes, it is equally as important to consume the right amount. If you take too much (or dilute) electrolyte drinks it prevents your body absorbing the fluids you have taken in. If you consume too little (or under dilution) you will not quite meet the demands of replacement. Follow the principles listed below as a general guideline:
- Consume around 500-700ml (approx. 16-24 oz.) of fluid per hour, for every hour of activity including the first hour. Increase this amount in hotter conditions.
- Try to sip about 5 to 6 ounces (or 2 to 3 gulps) every 15 minutes to optimize absorption. Larger athletes may need more, smaller ones potentially less, and everyone will need a bit more when the temperatures are over 75 degrees. Use your thirst as a guide.
- Do not leave your hydration too late into your workout. Your body cannot catch up under the conditions imposed by exercise.
Listen to your body. The smarter your rehydration strategy, the better your body will tell you on how to best care for it. Hydrate first and you may realize you do not need to eat as much as originally thought. In the heat, we lose fluid at a much faster rate than we burn through fuel. Think about the following fact: We can live for weeks without food but only days without water. Our physical performance drops easily and appreciably when we become dehydrated even with unused fuel supplies in the form of glycogen and fat stores. While you may find numerous arguments for one idea or theory versus another – it comes down to being your own scientific, real world experiment and that the best way to discover is to try for yourself. Also realize that this will be a work-in-progress and gets better over time. Before you go into your next goal event, make sure that you try out different strategies and products in a range of conditions and different types of workouts before you find something that you know your body agrees with.
Eat Real Food:
This of course, this leaves us with another question – how do we get enough calories in our body if we don’t drink those calories? Stay tuned until our September Blog.