Carbohydrate loading, or carb-loading, is a well-known method in the racing community. But, many racers may be doing it incorrectly. One of the most important things to note is everyone’s body is different, and it’s critical for all athletes to test any nutritional changes, well before race day. Devin RH Smith, M.D., UnityPoint Health, gives us five tips on carb-loading to maximize race day performance.
- Carb-loading is only recommended for events that last 90 minutes or more.
Dr. Smith says a person running a 5k for fun while trying to lose weight is not a good candidate for carb-loading, but a runner who is taking on a half marathon or greater distance could consider it. Carb-loading temporarily supercharges an athlete’s glycogen stores. Glycogen is a carbohydrate stored in muscle and the liver that is easily converted into glucose, which fuels muscle contractions and other biochemical processes needed for peak performance.
- Begin carb-loading three or four days before race day.
Most recommendations urge four to six grams of carbohydrates per pound of bodyweight per day. However, Dr. Smith again says it’s helpful to experiment well before race day arrives. That means the idea of carb-loading the night before the race by splurging on a big spaghetti dinner is not ideal.
“Anecdotally, I haven’t heard many good results with that; many runners report a single meal might increase negative side effects like bloating and gastric distress and may, in turn, actually hurt a runner’s performance,” Dr. Smith says.
- In general, aim for complex, unrefined carbohydrate sources.
This includes foods like beans, potatoes and grains. Many performance dietitians recommend foods with low glycemic indexes, with the idea being the more easily digestible carbs will simply spike your blood sugar and not be absorbed into the muscles and liver, whereas slower-digesting, fiber and nutrient-filled foods will slowly release energy over time and be more easily stored.
- However, be cautious of the amounts of fats and fiber you ingest.
Athletes need to watch what they’re putting on those grains and potatoes when carb-loading.
“The immediate danger of throwing in more fats and fiber is the intestines won’t be able to handle the abnormally elevated levels, leading to gastric distress, which is uncomfortable enough even when you’re not trying to run,” Dr. Smith says.
- Runners need to remember to replenish their glycogen stores while training and on race day, too.
Dr. Smith recommends a recovery drink as soon after an extensive workout as possible. It should include one gram of carbs per two pounds of bodyweight and one gram of protein per four to eight pounds of bodyweight per hour of exertion. As an example, a 175 pound person who just worked out for one hour should drink about 88 grams of carbs and 22 to 44 grams of protein after a workout for optimal recovery. This too is only a suggested starting-point, as athletes should adjust specific macros depending on their individual results.
“Carbohydrates and protein ingested immediately after exercise are preferentially shunted to the muscles and the liver through a process called nutrient partitioning, so the nutrients go to the hardest-working muscle to help repair and refuel,” Dr. Smith says.
Many athletes will also add high-glycemic, sugary intake directly before and during the race.
“Sugars in the blood-stream can be readily absorbed and used by working muscles on race day and add to the energy stored as glycogen. Many athletes used dehydrated fruits, gels or sports-drinks to get a relatively quick jolt of energy to stave off fatigue,” Dr. Smith says.
Experienced runners tend to experiment and find an amount of carbs that works for them, but a good rule of thumb is 0.5 grams of carbs per pound of bodyweight, per hour of exertion. In other words, that’s about 88 grams per hour during performance for a 175 pound athlete. The danger in taking too much is indigestion, and too little will simply not aid performance. Using these sugar sources is, again, another area that is good to test before race day arrives.
“Bear in mind, even the fastest-digesting sugar sources will take 30 minute to digest, hit the bloodstream and be absorbed and ready to use in the muscles. Many racers will begin their intake 15 to 30 minutes before start-time and take small amounts every 15 to 30 minutes thereafter,” Dr. Smith says.