Hydration is an important topic for athletes. Probably the only modifiable element that can improve (or worsen) performance. Get it right, an athlete may score a new personal record. Get it wrong and it might mean a painful cramp or a bout of extreme fatigue.
Hydration, electrolytes and performance, all three, go hand-in-hand. Below are some common myths related to hydration that we seek to dispel.
1. Water is all I need for hydration: Nobody can deny the need for water in hydration of athletes. Sweating essentially involves loss of water and electrolytes (particularly sodium and chloride) during exercise. However, replacement of water only, particularly in endurance athletes is not a standard anymore, and there is a reason for it.
Prolonged activity, such as a triathlon or a marathon leads to sustained loss of water and salt in the form of sweat. Human body almost always loses more water than salt, which maintains blood sodium levels still within a normal range. However, as the concentration of sodium rises due to ongoing water loss, so does osmolality of the blood.
This stimulates the thirst center in the brain, and triggers a response where the individual gets a stimulus to drink water. During the same time, vasopressin or antidiuretic hormone (ADH) is secreted from the brain. ADH prevents water loss from the kidney by concentrating the urine.
Under these circumstances, if only water in ingested (and retained at the same time), sodium in the blood can fall to a dangerous level. This condition is called hyponatremia and can lead to confusion, muscle cramps and may even require hospitalization.
It is now standard to replace the fluid and electrolyte losses during endurance race using an isotonic electrolyte-rich beverage to prevent the above complication.
2. I should keep drinking even if I am not thirsty: This is a mis-concept. Clearly, waiting till the last minute is not advised but hydrating “more” necessarily does not help.
Hydration should start at the beginning of the race and continued throughout the race at a sustained pace, driven by thirst. But over-hydration, i.e. drinking without any thirst, can lead to similar problem as hyponatremia, particularly if most of the liquid consumed is water.
Luckily, most of these changes in blood sodium are minor and improve in a few hours as the body eliminates some extra water that was ingested.
3. Electrolytes do not change performance: Hydration with water has been previously compared, both during athletic activities as well as during sustained heavy work in hot summer months.
A seminal study done in 1920s involved hydration of workers exposed to hot weather with saline infused water. This was done to prevent muscle cramps as workers drinking water in the summer heat were experiencing significant muscle cramps and would miss work. Simple addition of saline to drinking water prevented muscle fatigue in dehydrated workers and improved compliance.
Additionally, an intervention study at the university of Alabama showed hydration with an electrolyte drink significantly delayed the onset and intensity of muscle cramps in athletes exposed to high intensity exercise.
In 1960s, a physician at University of Florida, Dr. Robert Cade, noted that football players performed better in the summer heat when they were given a solution that contained sugar and common salt, as compared to water alone. This led to the birth of Gatorade® as we know it.
Identifying and utilizing the right amount of electrolytes in the sports drink is the most challenging task. Experts now claim that sodium and potassium alone are not enough in an electrolyte drink to rehydrate athletes. Instead, using an electrolyte powder such as MAGNAK® that utilizes magnesium in addition to a balanced ration of sodium and potassium, allows muscles to perform better by lessening painful muscle cramps from overactivity.
4. I need a lot of sugar in my hydration drink: A study done at the Gatorade Sports Institute looked at the replacement of sugars in hydration beverage. Athletes either had water for hydration or sugars (10 grams/ hour) mixed in water as the test. As compared to water, the sugary beverage improved performance in athletes.
The conclusion of this study was that a sustained carbohydrate intake in the hydration beverage is essential for athletes. Since then, athletes were told to ingest 10-15 g of carbohydrate per hour for peak performance. Anything less, would not allow for the maximal impact.
However, there was a fundamental problem with this study-- The control. Scientifically speaking, comparing water with “sugary water” is not an appropriate control to answer the question if sugar water is the most appropriate rehydration drink for athletes.
Enriching water with either electrolytes or with sugars alone, both, can improve performance to some degree by providing an additional source of energy. However, sugars and electrolytes are distinct nutrients and while each of them is important, a single ingredient cannot be superior to the other.
The real question with sugars is how much is truly required in a sports drink to have an impact? Sugar intake has been linked to obesity and metabolic syndrome in the western world. Clearly, studies to define the optimal concentration of sugars with and without specific electrolytes are needed in endurance athletes.
5. Caffeine is a must to get a kickstart: Fortunately, there has been a lot of awareness in this regard. Caffeine, in high doses (not just through a cup of coffee) is a diuretic. Which means it stimulates the production of urine and leads to a net loss of water from the body.
Additionally, being a stimulant, caffeine can accelerate the heart rate beyond what is already stimulated by exercise. For this reason, caffeine intake is best after the workout, not during.
And the fact that caffeine can allow the muscle glycogen to be repleted faster in athletes, makes a strong case to enjoy caffeine in a recovery drink.
By: Sourabh Kharait, MD, PhD-Founder/CEO.
Dr. Kharait is an MD and a practicing Nephrologist in Northern California. He completed his Residency in Internal Medicine and Fellowship in Nephrology from the University of California, San Francisco. He has a PhD in Molecular Physiology from the University of Pittsburgh and specializes in treating patients with electrolyte disorders and kidney diseases.
