Saturday, April 24, 2010


 This is the third in a series of articles concerning the Philippine Sports Science Conference 2010. Read the first, which is the introduction to the series and gives an overview of the conference, here, and the second, which talks about longevity, here.

The second talk in the Philippine Sports Science Conference 2010 was titled “the role of hydration in optimum performance” by Prof. Luz Felicidad Callanta, RND, who currently teaches at the University of the Philippines Diliman.

Continuing off of Dr. Varona’s train of thought, Prof. Callanta affirms that the body indeed only absorbs 30% of supplements consumed, and the rest is removed, usually by urination. One can check this by noticing the color of one’s urine after taking a supplement and after not taking a supplement. Urine is typically a light yellow color, but after consuming a multivitamin supplement, the yellow tint will be noticeably brighter and more pronounced, indicating that most of the nutrients were indeed, ejected instead of absorbed, by the body. In this respect, Prof. Callanta does indeed recommend the “food first” mantra and advises everyone else to do the same.

One of the primary reasons to stay hydrated is to allow the body to properly regulate its own temperature. The human body loses heat, and therefore stays cooler, through five methods:

1. Radiation – Heat is transferred from the surface of one object to the surface of another without actual contact; radiation is the primary way the body loses heat.
2. Conduction – Heat is transferred from the surface of one object to the surface of another through direct contact; heat loss through radiation can be 25 times greater in cold air than in cold water.
3. Convection – Cold air in immediate contact with the skin is warmed by the skin; heated molecules move away, cooler ones take their place, and the cycle repeats itself.
4. Evaporation – Body heat causes perspiration, which is lost from the body surface when it is changed to vapor; two – thirds of evaporative loss is through perspiration.
5. Respiration – Body heat lost through breathing; one – third of evaporative loss is through respiration.

Our focus, of course, is on evaporation, which is how our body stays cool when we perspire. There is a danger, of course, of too much sweating, since the body may lose too much of its fluids, resulting in dehydration, which may prove fatal. Dehydration can be classified as the loss of one percent or more of body weight through the perspiration. Aside from constant, monitored water breaks, another way that coaches and trainers can prevent dehydration is by weighing the athletes before and after training sessions and events. This can aid them plan out future sessions more properly if they discover that the athletes may be losing too much body weight due to perspiration.

Speaking of coaches and trainers, Prof. Callanta urges all those in the profession to not use dehydration as a form of punishment. Punishing athletes during training by preventing water breaks then expecting them to immediately perform better is incredibly stupid and dangerous. Athletes, of course, will only continue to perform worse the more dehydrated they become, as the body will naturally become weaker and weaker. Expecting them to perform contrary to that is downright ludicrous and may cause the athlete to collapse or even suffer a heart attack due to stress. This is something coaches normally would not want on their resumes.

During training, athletes should consume mostly water, and sometimes sports drinks, if the training session or event is particularly grueling. Homemade, natural fruit juices or shakes are actually more beneficial than sports drinks, as they provide the same benefits, but are much more healthful and do not contain any chemicals. Unfortunately, natural, homemade fruit juices and shakes are not nearly as convenient as the typical sports drink, which, neatly preserved, can be bought at almost any corner store, so athletes tend to favor them instead of the more natural and healthful alternative.

There is also the matter of people reacting differently to sports drinks. There have been noted cases over the years that some brands fail to properly hydrate some athletes, causing decreases in performance over time, while others have been known to cause adverse effects within the digestive system if consumed over a long period of time. These reactions are different for literally everyone for every brand of sports drink out there, so if the athlete has to consume a sports drink, he or she should properly experiment and find the best brand for his or her body during training. Discovering that one has an adverse effect to a particular sports drink brand during an event would be very bad, indeed.

As a general rule, one should drink 150 – 350 ml of water every 15 – 20 minutes during exercise, and even more if the training session is very intense and the temperature is high. If the training session or event continues for more than 90 minutes, then sports drinks, or even better, natural fruit juices or shakes should be consumed every 15 – 30 minutes (or more frequently if the temperature is particularly high) in order to not only prevent dehydration, but to properly counteract the body’s continued loss of nutrients.

Sports drinks are normally composed of carbohydrates and electrolytes, such as sodium and potassium. These need to be chemically balanced in order for the electrolyte ratio to be just right. Again, natural fruit juices and shakes do the same thing and are much healthier, plus you don’t need to worry about the electrolyte balance. Studies have shown that, among the existing brands today, Gatorade drinks seem to have the most balanced electrolyte ratios, so they’re generally the best choice.

There are three types of sports drinks:

1. Hypotonic – where the fluid content is less than concentrated than the electrolyte content. These are generally not recommended because they have been known to hamper performance and produce adverse effects.
2. Isotonic – where the fluid content has the same concentration as the electrolyte content. These types are more efficient when taken during training sessions.
3. Hypertonic – where the fluid content is more than the electrolyte content. These are best taken after training session.

Fortunately, most sports drinks are labeled properly and show what their proper ratios are. Pick the ones most applicable to you and stay away from the ones that aren’t recommended. If the brand doesn’t properly label their drinks, then stay away and pick those that do.

Consumed liquid stays within the body for approximately 30 minutes before it needs to be excreted from the body. One good trick that scientific studies have discovered is to drink at least two full glasses of water 30 minutes or slightly more before your bedtime. This will allow the body to stay properly hydrated during sleep while allowing the body enough room to process the liquid and urinate it before shuteye, thus preventing any late night bathroom breaks that may disturb one’s sleep cycle. Upon waking, drink the same amount of water to immediately hydrate your system once again. The body becomes dehydrated during the standard eight hour sleep cycle, so one has to immediately counteract this. Studies have proven that this trick can aid in the body’s longevity by promoting better circulation, thus allowing the heart to function more efficiently and even lower blood pressure.

Urination should normally occur within one to two hours. If it occurs much less than this, then it could be a sign of dehydration. Another way to tell is by its color. I the urine is light yellow, then your fluid levels are normal. If it is dark yellow, then it is a sure sign of dehydration. Being completely clear and transparent, on the other hand, means overhydration.

Overhydration, or hyponatremia, can be defined as an electrolyte imbalance within the body that can prove dangerous and sometimes fatal. Have you ever tasted your own sweat? It doesn’t taste exactly like the water you just drank does it? It has a slight salty taste, right? Well, that’s because certain nutrients in the body, including sodium are naturally excreted from the body during perspiration and urination. Hyponatremia is a very low amount of sodium, causing the body’s functions to become imbalanced. Sports drinks or fruit juices and shakes can easily counteract this but overhydration, or consuming too much water, has also been known to cause this.

Fortunately, accidentally overhydrating oneself is extremely rare and does not normally occur, so athletes should not fear consuming too much water and having hyponatremia. The body naturally expels too much liquid in the body through urination or perspiration, and the body normally replaces the sodium it’s lost (unless, again, there is an extreme amount of sweating, in which case, reach for those sports drinks or fruit juices) so there’s nothing to worry about. Instead, the athlete should fear having an electrolyte imbalance because of perspiring too much and having too little liquid in his or her body.

Workouts aside, though, how much water should one consume in a day? An average, sedentary individual usually has around a 2000 calorie energy expenditure during the day, which would require 8 – 10 full glasses of water on a daily basis. So, yes, the “drink eight glasses of water a day” has a false side to it in that it’s usually not enough for most individuals, unless you lie in bed all day. If you’re more active, and definitely consume more than 2000 calories a day (because you walk around during work, walk on the way to commute, walk around the malls during the weekend, etc) then you should definitely drink more than 10 glasses of water a day.

A key trick here is to listen to your body. So, you know that you should drink at least ten glasses a day, but what’s the optimum amount? You probably don’t need a hundred glasses, but you’re body will set you straight. It will naturally signal you when you’re thirsty. This is usually a sign that you’re already dehydrated, so listen to your body and drink some water, stat! Just follow your body and if you notice that you’re drinking more than ten glasses a day, then that’s fine.

Of course, then there are athletes who expend upwards of 10,000 calories a day due to intense, all – day training sessions. In this case, and following the generalization previously stated, they would need 40 – 50 glasses a day, which isn’t really unheard of, since many top athletes are known to consume gallons and gallons of fluids in order to stay properly hydrated.

So, in short:

1. The body naturally excretes 70% of supplements taken, so one should follow the “food first” mantra instead.
2. Athletes should stay properly hydrated during training sessions and events by taking constant water breaks.
3. Coaches and trainers should not punish their athletes by preventing water breaks.
4. Sports drinks are good for maintaining the electrolyte balance in athletes during hard training sessions and long events, but natural, homemade fruit juices or shakes are even better.
5. Drink at least two glasses thirty minutes or slightly more before going to bed, then drink the same amount immediately upon waking.
6. Overhydration is nothing to be afraid of since the body has natural functions to counteract it. Fear dehydration instead.
7. One should urinate every one to two hours. Urinating less can be a sign of dehydration.
8. Drink at least 10 glasses of water a day and listen to your body to discover the optimum amount.

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Hello, I'm Noel Blanco and I write Fitness Philippines. I have been involved in physical fitness for more than 10 years now and am currently taking up graduate studies on Exercise and Sports Science at the University of the Philippines. You can contact me at
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