If you are thirsty, it is too late, as you are already dehydrated!
As the weather warms up and we become more active with outdoor activities, the concerns of dehydration get well-needed attention. While most people rely on thirst as an indicator for the intake of fluids, it has been proven not to be an accurate indicator.
By the time you are thirsty, it is too late, your body has already experienced significant fluid loss. Medical studies have shown that thirst is not well correlated to fluid status, which in my opinion is a design flaw in us humans. Throw in the mix a little sweat on the hot, humid summer days in Cincinnati, and it is easy to find yourself in a fluid deficit and in need of a hydrating stimulus package.
Fluid intake is huge for those trying to lose weight and a local hospital-based weight loss program recommends 80 oz. per day. Patients of this program feel like they are swimming when they drink this much water, but it pales in comparison to the guidelines of other medically based resources. According to the Institute of Medicine, it is recommended to have a daily water intake of 125oz. for men and 91oz. for women, this can increase to 336 oz. if activities with high sweat loss are performed, such as a personal training session.
Dehydration caused by failing to replace fluids during activities also slows the body’s ability to dissipate heat, which can lead to a strain on the heart and possibly heat stroke. It is recommended to replace fluids at the rate for which they are lost. This can be accomplished by simply weighing yourself before and after your activity and replace the weight lost with the same amount of water. One quart of water weighs about two pounds.
As we age thirst becomes an even poorer indicator of fluid status so adequate water intake is especially important for the mature adult. We can survive losses of up to 40% of our body weight in fat, carbohydrate, and protein, but a water loss of 9% to 12% of body weight can be fatal.
One way is to monitor your fluid status is to look at the color of your urine first thing in the morning. If it is more the color of apple juice than that of lemonade, you may be dehydrated. Now you know why your pee is so dark after a night of boozing it up!
Of course, there are many fluids to hydrate with but since your body is 60% water, I personally believe plain water is king. Working with the overweight population a great deal, I often hear “I hate water!” If you are one of these people, I am worried about your future in the weight control department. Diet sodas have been linked to weight GAIN, and if you need a flavorful burst every time you are thirsty, it is going to be tough to control the calories.