Some athletes simply prefer drinking water to sports drinks during exercise. If you are one of these athletes, you need to use gels.In the sport of distance running today, the most problematic illegal performance-enhancing substances are recombinant erythropoietin (rEPO) and anabolic androgenic steroids. A century ago it was water. Believe it or not, until the second half of the twentieth century, drinking during races was widely considered to be unsportsmanlike, if not outright cheating. Many runners also considered it a sign of weakness. The prevailing mentality held that the fitter and tougher the runner, the longer he could go in a workout or race without giving in to his thirst. (I say “he” and “his” because there were very few female distance runners during the first several decades of the sport’s modern era, which dates from the late nineteenth century.) Consequently, in the old days, runners customarily avoided drinking while running.
Paradoxically, many of the same runners who believed that water offered an “unfair” advantage also believed that drinking while running was harmful to performance, and eschewed it for this reason as well. While recognizing the benefits of water with respect to body hydration, these runners were convinced that the cramping, bloating, and uncomfortable sloshing that it sometimes caused were too high a price to pay. Only when science was able to prove that dehydration was not only bad for performance but also potentially dangerous did attitudes and practices begin to change. In 1977, in reaction to this evidence, the International Amateur Athletic Federation finally relaxed regulations that until then had strictly limited allowable fluid intake during long-distance races.
By this time, a physician named Robert Cade at the University of Florida had created the first sports drink. Cade hypothesized that the addition of electrolyte minerals and carbohydrates to water would facilitate fluid replacement and provide an energy source to working muscles, thereby enhancing athletic performance and delaying fatigue better than water alone could do. He named the drink Gatorade, because it was first used by the Florida “Gators” football team.
Cade and other researchers tried various concentrations and carbohydrate combinations until they settled on a basic formula that maximized the rate of gastrointestinal absorption. This was important, because it resulted in faster delivery of nutrients to the blood and working muscles and minimized some of the classic gastrointestinal problems that were commonly associated with trying to drink on the run. Clinical trials of this revolutionary new sports fuel confirmed that it did indeed enhance athletic performance and delay fatigue better than plain water.
For this reason—and for several other reasons that I cite below—I believe that runners should use a good sports drink during most workouts and all longer races. Unfortunately, despite all we’ve learned in the past 50 years, most runners still drink nothing at all during the majority of their workouts and are as likely to drink water as anything else when they do drink. In my experience, the situation in which many runners are most likely to drink on the run is, ironically, during short to middle-length races (5K, 10K, etc.)—one of the few situations in which drinking anything does more harm than good. The objective of this chapter is to help you bring your hydration and nutrition practices during running into the twenty-first century, once and for all.
Quick: Name five benefits of using a sports drink during workouts and races. If you’re like most athletes, you can only name one or two. The benefit all athletes know about is hydration. Or do they? More than 30 years after Gatorade first hit the market, television commercials for the original sports drink are still driving home the point that it “hydrates better than water,” which I take as a sign that this remains news to many.
A second benefit of sports drinks that at least most runners know about (if not other athletes) is energy. Sports drinks contain carbohydrates, and carbohydrates are the body’s preferred energy source during intense activity.
Are there really three more benefits of sports drinks? Actually, there are now no fewer than seven proven benefits, which together should motivate you to make a good sports drink part of your daily training.
Perspiration is a vital cooling mechanism for the body. Almost three-quarters of the energy that working muscles release during running takes the form of heat waste. If this heat were allowed to accumulate in the muscles it would cause serious tissue damage. The blood carries some of the excess heat away from the muscles to capillaries near the surface of the skin. Sweat glands then take up some fluid from the blood, and with it some heat, and release it onto the surface of the skin where it evaporates. Finally, cooled blood flows back toward the core of the body to absorb and distribute more heat. The only problem with this mechanism is that it’s essentially self-sabotaging. The more you sweat, the more your blood volume shrinks, and the more your blood volume shrinks, the less heat your circulation can carry away from the working muscles, and the less effective perspiration becomes.
Runners often produce sweat at rates exceeding 1.5 liters per hour. About 10 percent of this fluid comes from water released when glycogen (the storage form of glucose in the muscles) is metabolized. Since this water serves no other function than assisting glycogen storage, its loss does no harm. But about 90 percent of sweat comes directly from the blood. Drinking while running can slow dehydration substantially. It can’t stop it, though, because the average runner is unable to tolerate drinking more than 500 to 700 milliliters per hour at moderate running intensities. Drinking any faster causes uncomfortable stomach sloshing and can eventually result in cramps, bloating, and nausea.
As already mentioned, sports drinks hydrate better than water. Why? Three reasons: First, fluids are absorbed through the gut and into the bloodstream faster when their osmolality closely matches that of the blood itself. Osmolality is the concentration of dissolved particles in a fluid. Sports drinks contain dissolved minerals (sodium, etc.) and carbohydrates, as does the blood itself, whereas water contains only trace amounts of various dissolved minerals and elements, so the latter can’t reach the bloodstream as quickly.
Sodium and other minerals also play important roles in regulating fluid balance in the body. In other words, they help determine how much fluid enters muscle fibers and other cells, how much remains in the blood, and so forth. Because sports drinks contain these minerals, they do a better job of allowing the body to maintain optimal fluid balance, which is an important aspect of hydration status. (It’s not just how much fluid is in your body that matters, but where it is.)
A third advantage of sports drinks over water with respect to hydration is that the sodium content of sports drinks stimulates thirst, so athletes usually drink more when they have a sports drink than when they have plain water.
Under most circumstances, consuming water is better than drinking nothing, but not always. During workouts and races that last 4 hours or more, “replacing” sweat with only plain water can result in a dangerous dilution of the blood. Hyponatremia, or water intoxication, is a potentially deadly condition that results when the sodium concentration of the blood falls too low due to prolonged sweating combined with excessive water intake. Symptoms include dizziness, muscle cramping, confusion, and stomach bloating. Severe cases can lead to seizure, coma, and even death.
Hyponatremia occurs most often during marathons, when runners are running longer and drinking more (water) than at just about any other time. Noncompetitive runners who require more than 4 hours to complete a marathon are most susceptible to hyponatremia. Nevertheless, it’s quite rare, and easily avoided if you simply drink sports drinks instead of water and drink according to your thirst rather than guzzling as much fluid as you can stomach. Preventing hyponatremia is not the most important reason to use a sports drink instead of water, but it is one more reason.
In long workouts, exhaustion can occur when the body’s very limited stores of glycogen run low. The carbohydrate content of sports drinks provides a ready supply of glucose to the blood that the muscles can draw upon for energy. This allows the muscles to conserve glycogen when the sports drink is consumed at frequent intervals throughout the workout or race. The result is greater endurance.
Sports drinks also allow runners to work at a higher intensity level (i.e., go faster) in shorter workouts and races wherein glycogen depletion is not a concern. Exercise scientists are still puzzled as to why this is so. The probable explanation is that the brain is able to read the inflow of carbohydrate into the liver as a sign that it is “safe” to allow the muscles to work a little harder.
A pair of contrasting marathon performances by American record holder Deena Kastor presents an interesting case study providing evidence of the additive benefit of consuming carbohydrate along with fluid during running. The first of these two performances was at the 2004 US Olympic Trials Marathon held in St. Louis, Missouri. Kastor began as a heavy favorite to win, her best marathon time being 9 minutes faster than that of her nearest rival. Shockingly, however, Kastor “hit the wall” in the final miles, slowed down considerably, and lost her lead to Colleen de Reuck. Apparently worried that a regular sports drink would upset her stomach, Kastor chose to drink Pedialyte in this race, which contains water and electrolytes but no energy.
Fortunately, Kastor held on for second place and still made the Olympic team—and learned her lesson. In the Olympic Marathon staged 6 months later in Athens, she chose to use Cytomax, a sports drink containing 7 percent carbohydrate in addition to water and electrolytes. Despite stifling 100-degree heat, Kastor was able to run the second half of the race faster than the first, moving her way up from 28th place at the 5K mark to 3rd place and a bronze medal at the finish. Kastor’s superior drink choice is almost certainly the primary reason she performed so much better in Athens than in St. Louis.
While carbohydrate is the muscles’ preferred energy source for moderate- to high-intensity exercise, during the latter portion of prolonged runs protein may supply as much as 15 percent of the muscles’ energy needs. Most of the needed protein is taken from the muscles themselves, resulting in muscle tissue damage, soreness, and fatigue. In other words, in order to provide the energy they so desperately need, your muscles essentially eat themselves.
Because muscle protein breakdown is linked to muscle tissue damage, and also because protein is a less efficient energy source than carbohydrate, the body only begins to rely heavily on protein for energy as a last resort, after carbohydrate fuel supplies run low. As blood glucose and muscle and liver glycogen levels fall, a message is sent to the adrenal glands to release cortisol, the stress hormone that is responsible for breaking down proteins into their constituent amino acids, which are then converted into glucose in the liver.
Using a sports drink during running reduces muscle damage. The carbohydrate provided in the sports drink slows the rate of glucose and glycogen depletion and thereby reduces cortisol release, sparing muscle cells from “cannibalizing” themselves for energy.
Recent studies have shown that when athletes consume protein along with carbohydrate and fluid during exercise, muscle damage is substantially lower and endurance significantly greater than when carbohydrate and fluid are consumed without protein, as in a conventional sports drink. In fact, in one study, muscle damage was found to be 83 percent lower and endurance 29 percent greater with a carb-protein sports drink than with Gatorade, which contains no protein. The authors of this particular study apparently saw no connection between these two effects, but it seems quite likely that the reduction in muscle damage was itself a major reason the subjects given the carb-protein sports drink experienced delayed fatigue.
There are two theories about how the addition of protein to a sports drink might reduce exercise-related muscle damage. The protein in the sports drink may be used preferentially for energy during extended exercise, resulting in less breakdown of muscle protein. The supplemental protein may also raise amino acid levels in the blood. Elevated levels of blood amino acids have been shown to reduce muscle protein breakdown.
Perceived exertion is how running feels on a comfort–discomfort continuum. Scientists measure it with various qualitative and quantitative scales, but the bottom line is that the higher the level of perceived exertion, the more miserable you feel. Perceived exertion is important not only because feeling good feels good and feeling bad feels bad, but also because lower levels of subjective discomfort are associated with better running performance. In the past, high levels of perceived exertion were regarded as merely an effect of the true physiological causes of fatigue (glycogen depletion and so forth). Now they are believed to be as much a cause of fatigue as events in the blood, muscles, and elsewhere.
As you run, your brain receives feedback information from the muscles, blood, and other sources and uses this information to determine whether the body is in any way endangered. If it is, the brain then reduces muscle fiber recruitment, causing either a small or drastic reduction of pace. It also produces feelings of fatigue and discomfort that reduce the athlete’s willingness to continue at the present pace. In Lore of Running, Tim Noakes, MD, puts it this way: “Fatigue is actually a central (brain) perception, in fact a sensation or emotion and not a direct physical event . . . [It] is merely the physical manifestation of a change in pacing strategy.”
Without question, muscle glycogen and blood glucose levels are two of the primary factors that affect the “pacing strategy” that the brain selects. When either the muscle glycogen or the blood glucose level falls too low, the brain simply causes fatigue in order to make the runner slow to a pace that he or she can sustain (hopefully!) to the finish line. Drinking a carbohydrate sports drink during prolonged running is proven to reduce perceived exertion levels by keeping blood glucose levels higher. Drinking plain water during running has also been shown to reduce ratings of perceived exertion, but to a lesser extent. Carbohydrate and water work independently in this regard.
Intense exercise suppresses the immune system for several hours. It does so by robbing the immune system of two of its principal fuels—glucose and the amino acid glutamine—and by stimulating cortisol release. One of the many effects of high cortisol levels is a reduction in immune system activity. This increases a runner’s risk of contracting infections and it also hampers recovery, as the immune system plays an important role in healing muscle damage after exercise.
Conventional sports drinks reduce immune system suppression by providing glucose and by limiting cortisol release. Sports drinks containing glutamine (or whey protein, which is rich in glutamine) give the immune system an additional boost.
Sports drinks allow for faster post-exercise recovery by limiting dehydration and by reducing glycogen depletion, muscle damage, and immune suppression. As a result, it takes less time to rehydrate, replenish muscle energy stores, repair muscle damage, and regain full immune function.
Believe it or not, using a sports drink during today’s workout can actually enhance your performance in tomorrow’s workout. It does this mainly by reducing muscle damage. Working out with residual muscle damage from previous training has been shown to reduce economy by 5 percent in runners, which is enough to severely compromise running performance.
Conventional sports drinks reduce muscle damage by delaying glycogen depletion and thereby reducing the use of muscle proteins for fuel. As discussed earlier, sports drinks containing amino acids or protein in addition to carbohydrate reduce muscle damage even further. Given their superiority in reducing muscle damage, it’s no surprise that carb-protein sports drinks have been shown to improve subsequent workout performance more than conventional sports drinks. In one study, athletes who used a carb-protein sports drink during a workout lasted 40 percent longer in a subsequent, exhaustive workout undertaken the following day than athletes who used a carb-only sports drink during the first workout.
Runners commonly assume that the reason they’re supposed to drink to prevent dehydration while running is because dehydration causes heat stroke. This is a myth.
To begin with, doctors no longer use the term “heat stroke” in reference to an athlete collapsing during exercise in the heat. They now refer to “exertional heat illnesses” in the plural. Exertional heat stroke is the most severe form of exertional heat illness, wherein overheating causes significant damage to body tissues. Heat exhaustion is the diagnosis given when body temperature rises high enough to cause collapse but not high enough to cause significant tissue damage.
The word “exertional” gets at the true cause of these conditions, which is the accumulation of heat produced by the working muscles. The harder the muscles work, the more heat they produce. In hot weather (especially hot, humid weather), this excess body heat does not dissipate well and as a result it accumulates in the body. Exertional heat illnesses are most likely to occur during very intense exercise, when the muscles are producing the most heat. In these cases collapse occurs relatively quickly—long before dehydration has a chance to develop.
During prolonged exercise, body temperature rises as dehydration progresses. This is to be expected, since sweating is an important cooling mechanism that becomes less effective the longer it continues. However, it only goes so far. Even severely dehydrated runners seldom experience heat illness, and those who do are seldom more dehydrated than those who do not. There is evidence that some athletes are particularly susceptible to heat illness and therefore experience it at dehydration levels that aren’t a problem for most.
This is not to suggest that dehydration is benign. The body temperature increase and the reduced blood flow that come with dehydration hamper running performance. And extreme dehydration can be fatal. However, athletic collapse is almost never caused by dehydration, which must exceed 15 percent to pose serious health risks. Very rarely do runners or other athletes reach levels of dehydration approaching even 10 percent. But dehydration levels of only 2 percent, which are very common during prolonged exercise, are sufficient to reduce endurance performance.
Drinking a sports drink during running lessens the performance-diminishing effects of dehydration and may slightly reduce the risk of heat illness in those who are susceptible. But the best way to prevent exertional heat illnesses is simply to avoid running in extremely hot weather, or at least to reduce the intensity and duration of your workouts in hotter weather.
It is possible to acclimatize to hot-weather running, and it’s a good idea to do this before participating in long races that may take place in warm or hot weather. Heat acclimatization reduces sweat rate and the electrolyte concentration of sweat, allowing runners to slow the dehydration process somewhat when exercising in a hot environment. This process consists of gradually getting used to running in the heat over the course of 10 to 15 days. Start with a very short run at a very easy intensity on the first day and gradually increase the duration and intensity of running from day to day until you’re able to run more or less normally in the heat.
Many runners believe that all sports drinks are essentially the same. They are not. Differences in formulations that seem subtle on the labels may translate into highly disparate effects on your performance. Whereas one brand of sports drink might enhance your marathon performance by several percentage points as compared to water, another brand might cause you to cramp up, vomit, and fail to finish. There are several very good sports drinks on the market, but some so-called sports drinks don’t even deserve the name. To make the best choice you need to know what to look—and look out—for on the labels. There are five items on this list: the types of carbohydrates, the concentration of carbohydrates, the amount of electrolytes, amino acids and protein, and useless extras.
The best types of carbohydrate for fueling exercise are those that are easily broken down and absorbed by the stomach and intestine. These include sucrose (aka dextrose or table sugar), glucose, and maltodextrin, which is also called glucose polymers.
There are some carbohydrates, even “simple sugars” such as fructose, that are not as easily broken down and are more likely to cause gastrointestinal distress. Fructose actually slows down water and energy absorption, hampering energy and fluid delivery to your muscles. In addition, fructose has to be transported to the liver and converted to glucose before your muscles or brain can use it, making it a less efficient energy source than other carbohydrates that can bypass the liver. Galactose is another sugar that must pass through the liver first.
If a sports drink label lists fructose (or high fructose corn syrup) as the first or only carbohydrate, beware: It could lead to problems during prolonged exercise. A small amount of fructose in a sports drink won’t cause problems as long as other, more easily absorbed sugars are also present. Fructose should be the second or third carbohydrate listed. Sucrose (dextrose), glucose, and/or maltodextrin (glucose polymers) should be listed above it.
A sports drink should also contain at least two, and ideally three types of carbohydrate. This is because different types of carbohydrate utilize distinct digestive pathways. If a sports drink contains only one type of carbohydrate, chances are it will overwhelm the pathway used to digest it, creating a backlog. But if a sports drink contains multiple types of carbohydrate, then multiple digestive pathways can process them simultaneously, so that glucose (always the end product) enters the bloodstream faster.
Runners typically burn 100 to 200 grams of carbohydrate per hour at normal training intensities. But the average runner can absorb only 60 to 80 grams of ingested carbohydrate per hour. This means that even under the best of circumstances, runners cannot absorb enough carbohydrate to completely offset carbohydrate losses during running. What’s more, even reaching the 60 to 80 grams per hour limit is far from automatic.
Two major factors affect how quickly carbohydrate is absorbed in fluid form. The first is stomach volume. The fuller your stomach is, the faster it empties. The second factor is the concentration of the fluid. Research has shown that carbohydrate is absorbed fastest when its concentration in a fluid is in the range of 6 to 8 percent (assuming normal drinking rates). Fluid itself is absorbed a little quicker when the carbohydrate concentration is somewhat less than 6 percent, but the actual rate of carbohydrate absorption is also a little lower because there’s simply less carbohydrate provided.
There are some sports drinks with carbohydrate concentrations as low as 2 percent. Although they are absorbed quite quickly, they simply don’t provide enough total carbohydrate and you should not use them unless you have a sensitive stomach and cannot tolerate sports drinks with the optimum 6 to 8 percent concentration.
In theory, a “sports drink” containing as much as 16 to 18 percent carbohydrate, although it is absorbed very slowly, could deliver carbohydrate at the maximum absorption rate of 60 to 80 grams per hour. However, it would require that a very large volume of fluid be maintained in the stomach, which is next to impossible during running. Consuming any sports drink containing more than about 8 percent carbohydrate at a realistic rate with a manageable stomach volume will result in a lower rate of nutrient delivery to the blood and muscles, and is more likely to result in GI distress.
Every sports drink should contain sodium, chloride, potassium, and magnesium. All four of these electrolytes are lost in sweat and your running performance will benefit from efforts to replace them. Only about half of the sports drinks on the market contain magnesium. Nearly all of them contain sodium and chloride (in the form of sodium chloride, or table salt), as well as potassium, but not always in adequate amounts. (Note that on most ingredient labels only the sodium content of sodium chloride is listed. Sodium and chloride exist in a 3:5 ratio in salt.)
The sweat of the average trained runner contains approximately 2,600 milligrams of sodium per liter, 1,100 milligrams of chloride per liter, 150 milligrams of potassium per liter, and 100 milligrams of magnesium per liter. In principle, a sports drink should contain these electrolytes in equal concentrations, but few existing sports drinks come anywhere close, in part because of palatability issues. My recommendation, therefore, is that you favor brands that contain the highest concentrations of electrolytes relative to the others.
Most sports drinks contain electrolytes in amounts that are adequate for normal training and racing. However, when you anticipate extreme sweat losses—for example in an ultramarathon—you will need to supplement your sports drink with salty foods such as pretzels (if possible) or salt tablets such as Lava Salts. In these circumstances, aim to take in 200 to 800 milligrams of sodium per hour.
Until recently, there was only one carbohydrate-protein sports drink on the market that I’m aware of: Accelerade. It contains 6 grams of whey protein per 12-ounce serving in addition to 7.75 percent carbohydrate. In independent studies (i.e., studies not funded by the manufacturer), this formula has been shown to drastically increase endurance and diminish muscle damage as compared to conventional sports drinks. One recent study found that it even hydrates better by boosting blood fluid retention.
There remains much to be learned about precisely how the addition of protein to a sports drink benefits athletes. New findings in this area may suggest further refinements in sports drink formulas. For example, it is probable that not every amino acid contained in whey protein carries a performance benefit. The sports drinks of the future will probably contain only select amino acids, not complete proteins. There is already research showing that the amino acids alanine and glutamine are especially beneficial during exercise. Cytomax contains both, and Revenge Sport contains glutamine, but in small amounts. E3 contains larger amounts of glutamine as well as the branched-chain amino acids leucine, isoleucine, and valine, which appear to be among the most beneficial amino acids to consume during exercise.
One more thing to look out for is “marketing ingredients”—ingredients manufacturers boast on sports drink labels because they have a reputation for healthful effects, but which actually have no effect on performance and/or are included in amounts too small to have any physiological effect. Ribose, creatine, ginseng, CoQ10, and carnitine are some of the ingredients added to drinks to boost sales, not athletic performance.
For example, ribose is a sugar that became popular particularly among bodybuilders after preliminary research suggested that it enhances muscle recovery. Subsequent research showed that it does not, but ribose-containing supplements remain popular and it can still be found in a couple of sports drinks. Not only is ribose useless in any amount as a performance aid, but the drinks that contain it do so in such small amounts (0.05 grams in one case) that it would be useless anyway. Another drink contains about 2 milligrams of CoQ10, a coenzyme that has never been shown to improve athletic performance, and even if you take it for health reasons (it’s an antioxidant), it needs to be consumed in amounts ranging from 30 to 100 milligrams.
The only ingredients besides water, carbohydrates, electrolytes, and protein/amino acids that are useful in a sports drink, based on current scientific knowledge, are the antioxidant vitamins C and E. These antioxidants are known to reduce exercise-related oxidative damage. However, it doesn’t make any difference whether you get them during exercise or at other times.
Carbohydrate gels are essentially sports drinks without the water. Some gels (e.g., Clif Shot) contain electrolytes, while others (GU, for example) do not. In order to be absorbed as quickly as sports drinks are, gels must be consumed with water. And, of course, you need water anyway for hydration. If you use a gel that does not contain electrolytes, you need to get them from another source. That source should not be a sports drink because the combined carbohydrate concentration of gels and sports drinks is too great for optimal absorption. One option is to wash down your gels with an electrolyte-fortified water such as Pedialyte.
Gels (when taken with water) provide the same benefits as sports drinks and should be taken in the same circumstances. But you must choose one option or the other. The only sensible way to “combine” the two is by following gel consumption with water consumption for the next 20 to 30 minutes and then switching to a sports drink once the gel has been digested. So, when might you want to use gels instead of sports drinks?
Some athletes simply prefer drinking water to sports drinks during exercise. If you are one of these athletes, you need to use gels.
In some circumstances, gels are more convenient than sports drinks. For example, you can easily carry enough gel packets to fuel a 3-hour run and stop at water fountains for the water you need instead of being saddled with 2 or 3 pounds of sports drink in a hydration belt or fluid bladder.
In races, if you are not a fan of the sports drink offered on the course, you can carry gel packets and just grab water cups from aid stations along the way.
In cool-weather workouts and races in which your sweat rate is relatively low but you’re still burning lots of carbs, gels can be preferable to sports drinks. In such cases you will take the gels with somewhat less water than you would take in warmer weather. While this will slow the absorption rate slightly, it’s better than having to urinate frequently, which is what will happen if you consume too much fluid while sweating lightly.
As already stated, I recommend that you use a sports drink during most if not all of your runs. Even in relatively short and easy runs wherein drinking will not affect your performance, it will still reduce muscle damage (especially if the drink contains protein) and accelerate recovery. You will also benefit from drinking in all races lasting an hour or more. Here are specific guidelines for drinking during workouts and races.
Use a fluid belt. The most convenient way to transport a sports drink on runs is to carry a squeeze bottle in a fluid belt. You can purchase these items at most running specialty shops. If you’ve never worn a fluid belt before or are not in the habit of doing so, you’ll find it takes some getting used to; the constriction of the belt and the weight of the bottle against your lower spine are somewhat uncomfortable at first. In fact, the relative inconvenience of drinking on the run is the main reason that only a small fraction of competitive runners do so, whereas in sports such as cycling, in which transporting a bottle is more convenient, drinking throughout every workout is an almost universal practice. Nevertheless, I am certain that the benefits of drinking during runs outweigh the inconvenience.
When you’re heading out for an easy run and you just aren’t in the mood to be weighed down with even 8 or 12 ounces of fluid, at least make the effort to take a few swigs of your sports drink right before you start and immediately after you complete the run. If you are able to plan a route that passes a water fountain where you can wash down an energy gel somewhere in the middle, so much the better.
Drink during all high-intensity workouts. Drinking during the run itself should be 100 percent routine in all high-intensity workouts (e.g., intervals on the track) and in all runs of any intensity lasting an hour or longer. In these circumstances, drinking will enhance workout performance and thereby boost the training effect of the workout, in addition to reducing muscle damage, limiting immuno-suppression, and accelerating recovery. In long runs on roads or trails, you’ll have to carry your drink. In high-intensity runs it’s prohibitively cumbersome to carry fluid, and it’s virtually impossible to drink while running at intensity levels above 10K race pace. I recommend doing these workouts at a track or other venue where you can stash a squeeze bottle in a handy place and drink from it during jogging recoveries. Drinking between high-intensity intervals has been shown to enhance performance even in workouts lasting significantly less than an hour.
Drink small amounts frequently. Try to drink every 10 minutes or so throughout your workouts. Drinking frequently keeps your stomach volume higher, resulting in faster delivery of fluid and energy to the muscles. The precise amount you drink is not especially important. Research has shown that results are usually best when athletes drink ad libitum—that is, according to their thirst.
One exception is especially long workouts and races (2 hours plus) undertaken in warm or hot weather. In these circumstances, you should make an effort to drink at a rate that’s as close as possible to your actual sweat rate. To determine your sweat rate, weigh yourself in the buff, on a scale with pounds and ounces, immediately before and immediately after a 60-minute run during which you do not drink. The number of ounces lost is your sweat rate per hour. Since your sweat rate is temperature-dependent, be sure to perform this test on a hot day if your objective is to figure out your target drinking rate for hot-weather running. Understand that it’s very unlikely you’ll actually be able to drink at 100 percent of your sweat rate while running; if you can comfortably replace two-thirds of losses you’ll be fine.
Drinking during workouts also lets you practice before you try it during races. Individual runners vary significantly with respect to sweat rates and the amount of fluid and carbohydrate intake they can tolerate while running. Therefore, you need to experiment during training and determine exactly what works best for you so that you can duplicate it as closely as possible in races. Being able to drink comfortably while running is also a trainable skill, so practicing will not only help you determine how much you can tolerate but may also increase your tolerance.
Begin drinking before you start running. The first thing you need to do when it comes to training your gut for races is to start thinking about the contents of your stomach, or bolus. Because your stomach empties faster when it’s fuller, it’s a good idea to practice beginning your workouts with a larger bolus than you’re used to having.
A sports drink is the ideal pre-run bolus builder because your bolus becomes running fuel as soon as you start running. The ideal time for bolus building is within minutes of beginning your run. Start by drinking a modest amount before running. Even a few ounces may feel uncomfortable at first, if you’re used to running on an empty stomach, but keep doing it and you should adjust. When you do adjust, try drinking a little more before running, and continue in this way until you’re confident you’ve found your personal limit.
Simulate race conditions. In at least some of your workouts, use the drink that will be offered at aid stations in the race you’re training for. (It’s usually named on the race Web site. If not, call the race management and ask.) If either your taste buds or your stomach does not react well to the race’s sponsoring sports drink, or if the drink is poorly formulated (based on the guidelines given above), practice with it just a few times and use your preferred sports drink in your other workouts. Another option is to carry energy gels during the race and take only water from the fluid stations, in which case you’ll need to practice using gels.
For drinking-practice purposes, carry or give yourself access to your sports drink during all of your long runs and race-pace workouts, because these are your most race-specific training sessions. It’s especially important to practice drinking at race pace, because the faster you run, the harder drinking is mechanically and the less nutrition your stomach can tolerate. Again, begin by drinking only a small amount that you know you can handle. In subsequent workouts, gradually increase your intake until you reach the limit of your tolerance, keeping in mind that it may take your body a few tries to get comfortable with any given intake level. Increase your intake primarily by drinking more frequently rather than by drinking larger amounts at a time, because you’ll maintain a larger bolus than you would if you drank the same amount but took larger swigs less frequently. Don’t drink more often than once a mile, though, because you want to simulate the feeding schedule provided by race fluid stations.
Drinking is not beneficial in races lasting less than an hour. For legal reasons most race directors provide fluid stations in races even as short as 5K, and a great many runners take advantage of them, but it’s silly. I can’t help suspecting that the runners who guzzle greedily from paper cups in 5Ks are the same ones who never drink in training.