The 10 Biggest Mistakes Endurance Athletes Make

Edition 7, 2005
By Steve Beaver Born

There are obviously more than ten mistakes that athletes can make, but those listed in this article represent the most common performance-ruining ones athletes have made over the years (I know I sure have made them!). Some of these may seem basic and obvious, but you'd be amazed how many athletes keep making the same ones over and over, and then wonder why their performance isn't as good as it could be.

Most of these "Bottom Ten" violate the most fundamental law of fueling physiology: we must consume each component of fueling in cooperation with the marvelous machine that is the human body. In our efforts to help our body, we often overcompensate, and don't realize until too late that we've done more harm than good. Your body is your primary reservoir of all nutrients; ignore that concept and you will absolutely suffer the consequences.

Carefully read through the description of each of these mistakes—at least some of them will sound painfully familiar! But we don't just tell you what you're doing wrong; each of the ten sections also tells you the appropriate corrective action to take. Follow this advice and you'll quickly see significant improvement in your overall performance.

Excess Hydration

Optimal nutritional support for endurance athletics means consuming the right amount of the right nutrients at the right time. You can neither overload nor undersupply your body without compromising athletic performance and incurring detrimental results. The principle of avoiding both too much and too little especially applies to hydration, where serious consequences occur from either mistake. If you don't drink enough you'll suffer from unpleasant and performance-ruining dehydration. Drink too much however, and you'll not only end up with impaired athletic performance, you may even be flirting with potentially life-threatening water intoxication.

One of the most respected researchers on hydration, Dr. Tim Noakes, studied the effects of thousands of endurance athletes and noted that the front-runners typically tend to dehydrate, while over-hydration occurs most often among middle to back-of-the-pack athletes. Both conditions lead to hyponatremia (low blood sodium), but through different processes. Excess water consumption causes what is known as "dilutional hyponatremia," or an overly-diluted level of sodium and electrolytes in the blood. This is as bad as under-hydrating in regards to increased potential for muscular cramping but has the added disadvantages of stomach discomfort, bloating, and extra urine output. And, as mentioned earlier, in some unfortunate circumstances, excess hydration can leads to severe physiological circumstances, including death.

Unfortunately, endurance athletes too often adopt the "if a little is good, a lot is better" approach. This can lead to significant problems when you're trying to meet your hydration requirements. All it takes in one poor performance or DNF due to cramping and you start thinking, "Hmm, maybe I didn't drink enough." Next thing you know, you're drinking so much water and fluids that your thirst is quenched but your belly is sloshing and you're still cramping. Remember, you can neither undersupply nor oversupply your body with fluids, so consume appropriate amounts.

How much should one drink? One expert, Dr. Ian Rogers, suggest that between 500–750 milliliters/hr (about 17–25 fluid ounces/hr) will fulfill most athletes' hydration requirements under most conditions. I believe all athletes would benefit from what Dr. Rogers says: "Like most things in life, balance is the key and the balance is likely to be at a fluid intake not much above 500 milliliters (about 17 ounces) per hour in most situations, unless predicted losses are very substantial." [Fluid and Electrolyte Balance and Endurance Exercise: What can we learn from recent research? by Ian Rogers,]

Recommendation: We at E-CAPS/Hammer Nutrition have found that most athletes do very well under most conditions with a fluid intake of 20–25 ounces per hour. Sometimes you may not need that much fluid (15–16 ounces per hour may be quite acceptable) sometimes you might need somewhat more, perhaps up to 28 ounces. Our position, however, is that the risk of dilutional hyponatremia increases substantially when an athlete repeatedly consumes more than 30 fluid ounces per hour. If more fluid intake is found to be necessary (under very hot conditions, for example) proceed cautiously and remember to increase electrolyte intake as well to match your increased fluid intake. You can easily accomplish this by consuming a few additional Endurolytes capsules.

Simple Sugar Consumption

We believe that fructose, sucrose, glucose and other simple sugars (mono- and disaccharides) are poor carbohydrate sources for fueling your body during exercise. Also, for optimal general health, you should restrict your intake of these simple sugars (see Dr. Bill Misner's article "113 Ways Sugar Can Ruin Your Health" in the Knowledge section at

For endurance athletes, the primary problem with fuels containing simple sugars is that they must be mixed in weak 6–8% solutions in order to match body fluid osmolality and thus be digested with any efficiency. Unfortunately, solutions mixed and consumed at this concentration only provide about 100 calories per hour, totally inadequate for maintaining energy production on an hourly basis. Using a 6–8% solution to obtain adequate calories means your fluid intake becomes so high to cause discomfort, bloating, and possibly oversupplying your body to the point of fluid intoxication.

You can't make a "double or triple strength" mixture from a simple sugar-based carbohydrate fuel in the hopes of obtaining adequate calories because the concentration of that mixture, now far beyond the 6–8% mark, will remain in your stomach until sufficiently diluted, which may cause substantial stomach distress. You can drink more fluids in the hopes of "self diluting" the overly concentrated mixture, but remember that you'll increase the risk of over-hydration. However, if you don't dilute with more water and electrolytes, your body will recruit these from other areas that critically need them and divert them to the digestive system to deal with the concentrated simple sugar mix. This can result in a variety of stomach-related distresses, not to mention increased cramping potential.

Simply put, simple sugar-based drinks or gels have to be mixed and consumed at very dilute calorically weak concentrations in order to be digested with any efficiency. A simple sugar-based product used at a properly mixed concentration cannot provide adequate calories to sustain energy production. Any way you look at it, fuels containing simple sugars are an inefficient, inappropriate way to fuel your body during prolonged exercise.

Complex carbohydrates (polysaccharides) are the wisest choice for endurance athletes, as they allow your digestive system to rapidly and efficiently process a greater volume of calories, providing steady energy. Unlike simple sugars, which match body fluid osmolality at 6–8% solutions, complex carbohydrates match body fluid osmolality at substantially more concentrated 15–18% solutions. Even at this seemingly high concentration, complex carbohydrates (such as maltodextrins and glucose polymers) will empty the stomach at the same efficient rate as normal body fluids and provide up to three times more energy than simple sugar mixtures, which means you can fulfill your caloric requirements without running the risk of over-hydration or a variety of stomach related maladies.

Recommendation: To get the proper amount of easily digested calories, rely on fuels that use complex carbohydrates (maltodextrins or glucose polymers) only, with no added simple sugar as their carbohydrate source. Hammer Gel and HEED are ideal for workouts and races of up to two hours. For longer workouts and races, select Perpetuem or Sustained Energy as your primary fuel choice.

Improper Amounts of Calories

Too many endurance athletes fuel their bodies under the premise, "If I burn 500–800 calories an hour, I must consume that much or I'll bonk." However, as Dr. Bill Misner says, "To suggest that fluids, sodium, and fuels-induced glycogen replenishment can happen at the same rate as it is spent during exercise is simply not true. Endurance exercise beyond 1–2 hours is a deficit spending entity, with proportionate return or replenishment always in arrears. The endurance exercise outcome is to postpone fatigue, not to replace all the fuel, fluids, and electrolytes lost during the event. It can't be done, though many of us have tried." In other words, your body can't replenish calories as fast at it expends them (ditto for fluids and electrolytes). Athletes who try to replace "calories out" with an equal amount of "calories in" usually suffer digestive maladies, with the inevitable poorer-than-expected outcome, and possibly the dreaded DNF ("Did Not Finish"). Body fat and glycogen stores easily fill the gap between energy output and fuel intake, so it's detrimental overkill to attempt calorie-for-calorie replacement.

Keep this in mind if you're doing ultra-endurance events, especially if you've had to "alter the game plan" and are unable to stick to your planned hourly calorie intake. For example, let's say you've been consuming an average of 280 calories an hour but the heat or other circumstances (such as climbing a very long hill) prevents you from maintaining that desired hourly average. DO NOT try to "make up lost ground" by consuming additional calories; it's not only unnecessary, it may very well cause a lot of stomach distress, which will hurt your performance. Remember, during periods where fuel consumption may be less than your original hourly plan, body fat stores will effectively fill in the gap, thus eliminating the need to overcompensate with calories.

Recommendation: Intake of 240–280 calories per hour, on average, is sufficient for most endurance athletes. Lighter weight athletes (<120–125 pounds) may need less, while heavier athletes (> 185–190 pounds) may need slightly more. Experiment in training to determine your specific requirements, using 240–280 calories/hour as a base to work from. If you fall behind on your average calorie intake, do not consume excess calories to bring your average back up.

Inconsistent Electrolyte Supplementation

Consuming sufficient calories and fluids during workouts and races is an obvious necessity. Consistent electrolyte supply is equally important. Just as your car's engine requires sufficient oil to keep its many parts running smoothly, your body requires electrolyte minerals to maintain smooth performance of vital functions such as muscle contraction. Athletes who neglect this important component will impair their performance, and may incur painful and debilitating cramping and spasms, a sure way to ruin a workout or race.

However, this doesn't mean that athletes should indiscriminately ingest copious amounts of one or more electrolytes (sodium or salt is usually the most misused). Supplementing with only one electrolyte or consuming too much of one or more electrolytic minerals overrides the complex and precise mechanisms that regulate proper electrolyte balance. The solution is to provide the body with a balanced blend of these important minerals and in a dose that cooperates with and enhances body mechanisms. Salt tablets alone cannot sufficiently satisfy electrolyte requirements and excess salt will cause more problems than it resolves.

Remember also that electrolyte replenishment is important even when it's not hot outside. Sure, you may not need as much as you would in hotter weather, but your body still needs consistent replenishment of these minerals to maintain the optimal performance of many important bodily functions. You don't wait until you dehydrate before you drink fluids, or until you bonk before you put some calories back in your body do you? Of course not. You fulfill those fueling requirements before the consequences of inadequate replenishment strike. The same logic applies to electrolyte replenishment. Going back to the engine/oil analogy, you don't wait until the engine seizes before refilling the oil reservoir and the same is true for electrolytes, the body's "motor oil," in that you don't want to wait until you start cramping before you replenish these important minerals.

Recommendation: Endurolytes, in either capsule or powder form, is an inexpensive, easy to dose, and easy to consume way to get your necessary electrolytes. Use Endurolytes consistently during workouts and races to fulfill this crucial fueling need.

No Protein Intake During Prolonged Exercise

When exercise extends beyond about two hours, your body begins to utilize some protein to fulfill its energy requirements. This metabolic process, called gluconeogenesis, allows for the synthesis of glucose from protein, helping to satisfy anywhere from 5–15% of your body's energy needs. If you fail to supply your body with protein from your fuel, it has only one other choice: your own muscle! Called "lean muscle tissue catabolism" or "muscle cannibalization," this process devastates performance through muscle deterioration and increased fatigue-causing ammonia accumulation, and also negatively affects the immune system and recovery. Carbohydrates are still the primary component of your fuel, but it should include a small amount of protein when training sessions or races last longer than two to three hours.

We believe soy protein's amino acid profile is ideal for use during exercise, which is why the Hammer Nutrition fuels, Perpetuem and Sustained Energy, contain soy as the protein source. For instance, compared to whey protein (which is ideal for recovery), soy protein has higher levels of phenylalanine, which may aid in maintaining alertness during ultra-distance races. Soy protein has higher amounts of histidine, which is part of the beta-alanyl l-histidine dipeptide known as carnosine, which has antioxidant/acid buffering benefits. Finally, soy protein has higher levels of aspartic acid, which plays an important role in energy production via the Krebs Cycle.

Dr. Bill Misner writes, "Soy's remarkable donation to endurance performance is deserving of our review. Soy has been observed to produce a higher degree of uric acid content than whey proteins. Uric Acid is reduced by excessive free radicals produced during exercise. When uric acid levels are higher, that is an indication of less free radical release due to antioxidant influence of the isoflavones found exclusively in soy. This is one reason why soy may be the preferred dietary protein application during endurance exercise demand."

Recommendation: Using Perpetuem or Sustained Energy as your primary fuel during workouts and races longer than two to three hours will satisfy energy requirements from a precise ratio of complex carbohydrates and soy protein, the latter of which helps protect against excess muscle breakdown. You stay healthier, reduce soreness, and decrease recovery time.

Too Much Solid Food During Exercise

In the 1985 Race Across America (RAAM), Jonathan Boyer rode to victory using a liquid diet as his primary fuel source. Since then it has become the norm for endurance and ultra-endurance athletes. Liquid nutrition is the easiest, most convenient, and most easily digested way to get a calorie and nutrient-dense fuel. Solid food, for the most part, cannot match the precision or nutrient density of the best liquid food fuels. In addition, too much solid food consumption will divert blood from working muscles for the digestive process. This, along with the amount of digestive enzymes, fluids, and time required in breaking down the constituents of solid food can cause bloating, nausea, and/or lethargy. Lastly, a good portion of the calories ingested from solid foods is used up simply to break down and digest them; in essence, these calories are wasted.

So while some solid food intake can be a welcome diversion during ultra-endurance efforts, we don't recommend it as your primary fuel source. Inasmuch as exercise diminishes digestive system functioning to begin with, regular solid food intake should be limited (the exception, not the rule) in your fueling strategy because of the increased the likelihood of performance-inhibiting stomach discomforts such as bloating, stomach cramps, nausea, and lethargy.

Recommendation: Use Hammer Gel, HEED, Sustained Energy, and/or Perpetuem as your primary fuel source during exercise. These provide precise amounts of specific nutrients and are designed for easy digestion, rapid nutrient utilization, and less chance of stomach distress.

Using Something New In A Race Without Having Tested It In Training

The title is pretty self-explanatory; it's one of THE cardinal rules for all athletes, yet you'd be amazed how many break it. Are you guilty as well? Unless you're absolutely desperate and willing to accept the consequences, do not try anything new in competition, be it equipment, fuel, or tactics. These all must be tested and refined in training.

Recommendation: Because all the Hammer Nutrition fuels are complementary (they all work well alone or in combination), you have all the flexibility you need to ensure that you can tailor a fueling program for any length of race, regardless of conditions. You'll never have to guess or grab something off the aid station table in hopes of trying to keep going another hour. Use Hammer fuels, try all sorts of combinations in training, and keep a log of what works and what doesn't. If you expand your training log to include fuel intake also, you'll have the data you need to prepare a fueling protocol for your next event.

Sticking With Your Game Plan Even When It's Not Working

Endurance athletes tend to be strong-willed and uncompromising. Most strive to have a "game plan" in place for their training program, which is, of course, an excellent idea. Wise athletes also have a game plan for their supplements and fueling. Having this nutritional game plan that you've honed during training is a big step toward success on race day, but don't slavishly adhere to it during the race if it's not working. What does fine in terms of fueling—your hourly intake of fluids, calories, and electrolytes—during training at a slower pace and lower overall energy output might fail during competition. Athletes who stubbornly maintain the same fuel intake hour after hour, even when it's clearly not working, end up with poorer results, if they finish at all.

Yes, it's important to maintain consistent caloric intake during a workout or race, but if the weather gets hot, the body's ability to process fuel becomes compromised. It's important to recognize this and to listen to your body. Continuing to force down "X" amount of calories an hour (the original "game plan"), especially under extreme conditions when your body cannot properly assimilate them, puts a burden on your stomach and can cause any number of stomach-related maladies, which will certainly hinder or ruin performance. During the heat, it becomes more important to stay hydrated and maintain adequate electrolyte levels, so be willing to cut back on calorie consumption. Body fat stores, which satisfy up to two-thirds of energy requirements during exercise, will accommodate energy needs during occasional breaks from regular intervals of fuel consumption. During the heat, fueling is still important, but the focus shifts towards maintaining hydration and proper electrolyte levels. Resume regular caloric intake when you start feeling better and your stomach has had some time to assimilate the fuel it already has.

In a similar, but "non-fueling" vein, another time when it's not a wise idea to stick to your original game plan is in training, especially after you've had a poorer-than-expected race. Many athletes think the cure for a poor race is to train harder and longer. Instead of recuperating, many athletes will train themselves into the ground, oftentimes ending up not fitter, but over-trained and with a poorly functioning immune system. A better tactic is to recuperate completely after your race, evaluating what went right and what went wrong during the race, and adapting your training accordingly; training harder and longer isn't necessarily your best option. Remember that recovery is as important a part of your training and the achievement of your athletic goals as the actual training session. Make sure you take your recovery as seriously as your training.

Recommendation: It's a good practice to have a game plan that includes a fueling protocol that you have refined during training, but you need to be flexible. Evaluate and adjust accordingly as race pace and weather dictate. Have a game plan, but write it in pencil, not in ink.

Inadequate Post-Workout Nutrition

Performance improvement depends on a program of exercise to stimulate muscular and cardiovascular adaptation followed by a recovery period in which the body rebuilds itself slightly more fit than before. Thus, the real gain of exercise occurs during recovery, but only in the presence of adequate rest and nutritional support. Athletes who fail to replenish carbohydrates and protein shortly after workouts will never obtain full value from their efforts. So even though all you may want to do after a hard workout or race is get horizontal and not move for several hours, you must first take care of what might be the most important part of your workout: the replenishment of carbohydrates and protein.

Carbohydrate replenishment as soon as possible upon completion of the workout (ideally within the first 30 minutes) takes advantage of high glycogen synthase activity, imperative to maximizing muscle glycogen, the first fuel the body uses when exercise commences. Protein supplies the amino acids necessary to (a) maximize glycogen storage potential, (b) rebuild and repair muscle tissue, and (c) support optimal immune system function.

This is also an ideal time to provide the body with cellular protection support in the form of antioxidants. Because athletes use several times more oxygen than sedentary people, they are more prone to oxidative damage, which not only impairs recovery but is also considered a main cause of degenerative diseases. Consistent supplementation with a full spectrum vitamin/mineral supplement, along with any additional antioxidants, boosts and maintains the immune system and reduces recovery time.

The bottom line is that post-workout nutrition is an important component of your training, and properly done, allows you to obtain maximum benefit from your training.

Recommendation: Consume 30–90 grams of complex carbohydrates and 10–30 grams of protein (a 3:1 ratio of carbohydrates to protein) immediately after workouts. This is easily accomplished with Recoverite, the all-in-one, complex carbohydrate/glutamine-fortified whey protein recovery drink. You can also prepare a variety of different flavored, easily made, and rapidly assimilated post-workout drinks using Hammer Gel or HEED for your carbohydrate source and Hammer Whey for protein. Or try this delicious/nutritious combination: 2–3 scoops of Sustained Energy plus 1–1½ scoops of Hammer Whey in orange juice. Supplements to consider for providing antioxidant support are the E-CAPS products Premium Insurance Caps, Race Caps Supreme, Mito-R Caps, Super AO, and Xobaline.

Improper Pre-Race Fueling

Far too often, athletes put themselves at a "metabolic disadvantage" during a race by fueling improperly prior to the race. The article, "The Pre-Race Meal," which you'll find later in this booklet, discusses this in greater detail, but we mention it here as well because it's definitely one of the biggest fueling errors athletes make. It's also one that is super easy to remedy. Let's look at the two primary factors:

  1. Over-consuming food the night before the race in the hopes of "carbo loading." It would be nice if you could maximize muscle glycogen stores the night before the race, but human physiology doesn’t work that way. Increasing and maximizing muscle glycogen stores takes many weeks of consistent training and post-workout fuel replenishment. Excess consumed carbohydrates are only going to be eliminated or stored as body fats (dead weight).

  2. Eating a pre-race meal at the wrong time. Let's assume you've been really good—you've been training hard (yet wisely) and replenishing your body with adequate amounts of high-quality calories as soon as possible after every workout. As a result, you've now built up a nice 60–90 minute reservoir of premium muscle glycogen, the first fuel your body will use when the race begins. A sure way to deplete those hard-earned glycogen stores too rapidly, which is definitely not going to help your performance, is to eat a meal (or an energy bar or sports drink) an hour or two prior to the start of the race.

Recommendation: Don't go overboard with your food consumption the night before the race. First rule: eat clean, which means no refined sugar (skip dessert, or eat fruit), low or no saturated fats, and no alcohol. Second rule: eat until you're satisfied, but not more.

If you're going to have a pre-race meal the morning of your race, you need to finish it at least three hours prior to the start of the race. If that's not logistically feasible, have a small amount (100–200 calories) of easily digested complex carbohydrates 5–10 minutes prior to the start. Either of these strategies will top off liver glycogen stores (the goal of the pre-race meal) without screwing up how your body burns its muscle glycogen.

Steve Born is a technical advisor for Hammer Nutrition with over a decade of involvement in the health food industry. He has worked with hundreds of athletes—ranging from the recreational athlete to world-class professional athlete—regarding their supplement/fueling program. Steve is a three-time RAAM finisher, the 1994 Furnace Creek 508 Champion, 1999 runner-up, the only cyclist in history to complete a Double Furnace Creek 508, and is the holder of two Ultra Marathon Cycling records. In February 2004 Steve was inducted into the Ultra Marathon Cycling Hall of Fame.

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