Tests indicate that drinking sport drinks does not create potential health hazards for diving enthusiasts. Although not harmful, sport drinks are incapable of sufficiently improving the ability of divers.
Sport electrolyte drinks are:
a.) Helpful to divers b.) Harmful to divers c.) Neither a.) nor b.)
Hot weather is on its way. Even more, divers need to think about replacing fluids. Which are best? Are sport drinks helpful or harmful? What’s the difference between an electrolyte drink and a carbohydrate replacer? Is beer a good carbohydrate replacer? What the heck is an electrolyte anyway?
Table of Contents
What Do You Need To Replace?
You need to replace body water before, during and after activity in the heat. Depending on how long and how intensely you exercise your athletic performance may benefit by adding electrolytes and carbohydrates. After exercise you need to drink water and restock the carbohydrates you used for fuel. There are several kinds of drinks available to benefit different durations of exercise and at various times.
Kinds Of Drinks
Water: The most overlooked athletic ability aid is water. Replacing lost body water reduces your chance of overheating, fatigue and generally feeling crummy in the heat. Compared to your body fluids your sweat is dilute or hypotonic. The word “hypo” means low and “tonic” refers to the concentration of blood minerals. When you sweat you lose proportionately more water than minerals, leaving your blood more concentrated than normal, or hypertonic. You need water. Your next meal will replace the other things you need.
Electrolyte replacers: You usually eat and drink more minerals called electrolytes in your regular meals than you need for normal daily activities – including diving. Exercise such as diving does not sufficiently deplete electrolytes to affect your athletic ability or your health.
During long, hard endurance exercises in the heat – such as 26 mile runs or 100 mile bike rides – you can lose enough electrolytes and water to slow you down. On the one hand, losing electrolytes with sweat is a good thing because if you didn’t your blood concentration would rise, too. But, if you don’t replace electrolytes, their level may fall too low and your athletic performance will suffer. Electrolyte drinks provide mineral and fluid replacement without you needing to stop to eat.
What is an electrolyte? It is any substance that, in water, dissociates into electrically charged particles called ions that can conduct an electric current. Why does your body need an electric current. Why does your body need an electric current? To conduct every nerve impulse and contract every muscle. The difference between current in electronic equipment and in your body is that electronic signals race through wire by movement of electrons. Nerve signals propagate more than 1,000 times more slowly along dissolved ions (average neural response time is about a millisecond or 0.001 seconds). Sodium and potassium are two of the principle positively charged ions in your body. Magnesium and calcium are two more. Chloride and bicarbonate are two important negatively charged ions.
Our chart shows the relative amounts of four electrolytes in your blood, sweat and, for comparison, in sea water. Note the relatively low amount in sweat compared to blood plasma. Also note that, contrary to popular belief, your blood is not similar in composition to sea water.
Carbohydrate loaders: Because athletes exercising at high intensities for long periods can delay fatigue with carbohydrate drinks and thereby work longer and harder, misunderstandings result. Drinking these preparations will not turn you into a better athlete or diver. Exercise ability does not improve from any particular food or drink.
What are carbohydrate loaders? They are sugar water. Sugars are the simplest carbohydrates. Carbohydrate loaders have three main applications. 1.) During intense, long duration exercise they provide fuel – which delays fatigue. 2.) For athletes who just can’t eat enough calories through regular meals and snacks to maintain weight during strenuous workouts, the drinks add calories. 3.) For people unable to eat a regular meal before physical activity because of time restraints or jittery stomachs, the drinks become a temporary meal substitute or adjunct.
When are carbohydrate loader drinks most effective? When the carbohydrate concentration is between 6 and 8 percent and when the exercise you’re doing is tough and lasts more than an hour.
There are some things the drinks won’t do. Carbo drinks won’t help just before or during exercise shorter than about 90 minutes, such as a sport dive, aerobics class, an hour of cycling, skiing, basketball or even a ten mile jog. Athletes have enough muscle glycogen to last about 90 minutes. Studies have found these drinks do not affect body core temperature, heart rate or sweat rate any differently than regular water. Because the drinks are simple carbohydrates and have no fiber compared to complex carbohydrates like potatoes, pasta, rice and corn, your blood sugar may vary enough to make you moody and extra hungry.
Carbohydrate replacers: Carbohydrate replacement drinks are different from carbohydrate loader drinks. They have a much higher carbohydrate content. Replacement drinks are for after hard activity to restock a carbohydrate in your muscles and liver called glycogen. Glycogen is an important fuel. Long, intense exercise depletes glycogen. You need to replace it as soon as possible after exercise. If you don’t eat enough carbohydrate your body won’t make enough glycogen to replace the loss. Your muscle and liver reserves will remain low even days later, limiting your exercise potential.
The first 30 minutes after hard exercise are crucial to the major restocking. The next two hours are the second important stage. Unfortunately, during this time people usually change their clothes and return home before eating anything. By then a critical maximum restock window has passed. For this reason extremely high carbohydrate replacement drinks were developed for right after exercise. Regular food eaten with water would do just as well. Replacement drinks serve the market of people who prefer to drink rather than eat right after exercise. The high carbohydrate content means the drinks are high calorie. If you go overboard with these the extra calories will store not as glycogen but fat.
Alcoholic drinks: Alcohol has several characteristics that make it unsuitable as a sport drink. Taken before an activity it reduces output of glucose by your liver, producing early fatigue. It is unsuccessful as a loader or replacer drink because, although alcohol is a concentrated source of carbohydrate calories, they are not metabolized like carbohydrate, making it ineffective as an endurance energy source. The electrolytes are insufficient for replacement. As a central nervous system depressant, alcohol interferes with mental and motor control. The well-known “beer-in, beer-out” phenomenon contributes to water loss when you need it most. Alcohol’s place is not with diving or exercise.
Caffeine drinks: Some results of past research indicated that caffeine helps athletic endurance. However, since it also increases irregular heartbeats, nervousness and urine output (called diuresis), if you don’t already drink coffee, tea or soda don’t do it just to get a boost for diving. If you already drink them cut down if you comfortably can. If you are so accustomed to your caffeine fix that missing your dose would hinder your diving, drink extra water to help offset the diuresis.
Not Harmful To Divers
Although not as helpful to everyday exercise or diving as we wish, commercial sport drinks are not harmful. They will not overload you with electrolytes, dehydrate you or sit in your stomach as sometimes thought.
Won’t harm blood electrolytes: There’s little risk of injurious electrolyte concentrations even from high concentration drinks. As a point of reference your body has about 97,000 milligrams (mg) of sodium and about 170,000 mg of potassium. In one hour of light exercise you might sweat between 400-700 mg sodium and 80-200 mg potassium. Contrast that with one cup of cream of mushroom soup with 1,000 mg of sodium. Sport drinks have far less sodium than that. A chart of electrolyte compositions of commercial sport drinks follows.
Your body continually makes adjustments to keep all its workings in a narrow range of sameness. When you are inactive the major exit avenue for surplus electrolytes is urine and feces. When you are active your body adjusts to restrict this loss because of sweat output. When you sweat and your supply of sodium falls below normal your body secretes a hormone called aldosterone (al-dohs’-tur-own) into your bloodstream to help you retain sodium.
If you eat more salt than you require, your body retains water to dilute the salt and aldosterone drops to encourage your kidneys to eliminate the excess. A limit exists, of course. Drinking sea water is one example. Salt concentration in seawater is about three percent. Human kidneys can’t produce urine more than two percent salt. Your kidneys draw water from your body’s supply to dilute the salt, a dehydrating process. The inability to drink seawater for fluid replacement is reflected in Samuel Taylor Coleridge’s ballad Rime of the Ancient Mariner – “Water, water everywhere, nor any drop to drink.”
Won’t dehydrate you: Unlike seawater, sport drinks won’t dehydrate you as a consequence of their electrolyte or sugar content. Neither is present in enough concentration. Sugar is not a diuretic. This myth may have gotten its start in hospital settings when solutions of 50 percent sugar (usually sorbitol or mannitol) were injected into a vein. This extreme concentration, as with sea water, makes you eliminate water. Sport drinks are usually 6 to 10 percent sugar. Even fruit juices and non-caffeine sodas that range up to 25 percent sugar will not dehydrate you. Sport drinks won’t dehydrate simply because they contain sugar. They replace needed water and the salt, carbohydrate and sugar content help retain that water.
Upset stomach: Although hard to tell in every case, studies of marathon runners reveal the usual culprits in gastrointestinal upset are high core body temperatures, dehydration and decreased sweating at high levels of dehydration – not sport drinks.
Sport drinks may leave the stomach slightly slower than water because of the calorie content. However, once in the small intestine the glucose and sodium speed up absorption. The slight difference in stomach emptying should not cause major upset in most people. Drinks of six percent sugar such as Gatorade enter the blood as fast as plain water. Recent studies on drinks that use small chains of sugar called glucose polymers show they are no more or less rapidly absorbed and no more or less effective than other drinks.
Not Crucial To Divers
Sport drinks won’t hurt divers but neither are they critical to optimum diving exercise capacity. Yes, it’s possible to sweat underwater. However, divers rarely overheat underwater enough to sweat greatly. Topside sweating is common. The possibility of electrolyte disturbance from such sweating is low unless you work slinging tanks in the tropics with limited chance to eat and drink fluids other than water.
After a one hour dive you don’t need to immediately add electrolytes. You haven’t lost enough to affect your performance or fatigue level. Your next healthy meal replaces nutrients for your next set of dives. However, you do need water.
What Should Divers Do?
OK, so sport drinks won’t make you a super diver. On the positive side they’re portably packaged, make hydration fashionable and easy, come in pretty colors and live up to claims for ultra-long endurance events where you can’t stop to eat or drink.
Specific recommendations are difficult to make but potential for harm is low. If you like sport drinks and they are your preferred method of hydration in the heat, enjoy yourself. Which drink you choose is a matter of personal taste. Also make an effort to drink water. Adequate water reserves are your hot weather friend for cool and healthy diving.