Carbs on the Run = Performance Gains

Hi, Friends & Fellow Runners:

Let’s first address the elephant in the room as far as nutrition and running are concerned.  No one talks or writes about it, but the fact of the matter is that a runner’s diet doesn’t quite fit a professional nutritionist’s definition of healthy eating.  Some purists might say it doesn’t even come close.  That’s because runners and other endurance athletes need carbohydrates and plenty of them.

Most nutritionists tell us that carbohydrates should represent no more than 35 or 40% of the macronutrients we consume (with protein and fats making up the balance).  But a serious runner needs to increase that percentage to about 50% during most of a training cycle and then, in the last two weeks before a race, to 55 or 60%.

Carbs enter our body’s bloodstream as glucose and are stored in our liver and muscles as glycogen.  Their major reason for existence is to serve as an energy source.  And unlike our body fat, the only other fuel for running, they are always in short supply during long training sessions and distance races. 

Despite their obvious benefits, however, carbohydrates are often given short shrift in treatises on weight control and proper nutrition.  Sugar is a carbohydrate, for one thing, and sport-engineered products such as energy drinks and gels depend on sugar for their effectiveness.  As well, carb-rich foods like the three P’s of pancakes, potatoes and pasta rarely head anyone’s list of healthy food choices.  But at the end of the day you can take the following statement to the bank:

Carbohydrates are, without a doubt, the most important fuel for an endurance athlete.  To deny that is to deny science.  They are the single most powerful nutrient for replenishing glycogen stores, extending time to exhaustion, increasing immunity during and after exercise, and improving performance.  Period.  End of story.

That’s why, if you want to perform well in any distance race from a half-marathon to an ultra-marathon, you must get into the habit of consuming carbohydrates on the run.  At least 40 to 60 grams of the nutrient are what you need per hour to maintain a strong and consistent pace while engaged in a race or training run of more than 75 minutes in duration.

Here’s how the cause-and-effect link between carbohydrate intake and enhanced performance was described in a recent issue of 220 Triathlon, a British magazine:

“The reason for the benefits of carbohydrate use during exercise is straightforward; muscle carbohydrate (more commonly called glycogen) is your body’s ‘premium grade’ fuel, especially when those muscles are working hard, such as during a race.

“However, your muscles can only store around two hours’ worth of glycogen.  And because even mild glycogen depletion is known to impair performance, using carbohydrate drinks or gels to replenish your carbs on the move....helps to delay the onset of fatigue and thus improves performance.”

The magazine gets very specific on the nature of that improvement.  It states, by way of example, that runners able to complete a half marathon in two hours (120 minutes) while consuming only water or nothing at all could better their finishing times to the following extent by ingesting carbohydrates:

Grams per Hour          % Improvement          Performance Gain

20                                2.0%                            2.40 minutes

40                                3.5%                            4.20      “

60                                4.3%                            5.16      “

After 60 grams, further carbohydrate consumption leads to little additional improvement, and after 80 grams the percentage improvement actually declines (apparently because too many carbs in too short a time tends to cause stomach distress.)

Reaching the recommended allotment of 40 to 60 grams of carbohydrates per hour while running could be as simple as combining 8-ounce Fuel Belt bottles of a sports drink (about 10 grams per bottle) and packets of energy gel or beans (27 grams each).   Or you could include in the mix everyday food items like a medium-sized banana, granola bar, quarter-cup of dates, small box of raisins or four Fig Newton’s – each of which provides about 30 grams of carbs. 

Determining an effective nutrition strategy for an endurance race is a matter of testing and practice.  The objective is to consume the needed carbs conveniently, quickly, and with no accompanying stomach distress.  Test yourself and find out what works for you in terms of food, gels, sports drink, etc. (as well as water).  Practice with different combinations on your weekly long-distance runs until you’re satisfied that you’ve found the one that suits you best.  And remember, a successful approach to carbohydrate consumption during a race of two hours or more is an absolute necessity if you hope to do your best.

Coach Stephen