Healthy Runner’s Diet for Optimal Performance with Christie Clinic


By Laura Jacob, MS, RDN, CDCES, Dietitian at Christie Clinic

Runners often ask me, a registered dietitian, what type of diet they should follow for proper nutrition and optimal performance. How runners fuel their body for running depends on the distance and the type of training schedule they’re following. There is a big difference in the nutritional needs of marathoners and those running shorter distances.

First, for runners and non-runners alike, the foundation of healthy eating is vegetables, fruits, whole grains, lean proteins, some healthy fats, and foods high in calcium. And don’t forget water! Following a healthy eating pattern also means limiting intake of processed foods as well as foods high in saturated fat, sodium, and added sugar. For many people, lower carbohydrate diets may be fine, but they are not recommended for runners. Carbohydrates are required for sustained, higher-intensity activities. If runners don’t take in enough carbs, they’re likely to run out of steam and not achieve the distance or speed they were shooting for. Healthy carb sources include whole fruits, vegetables, beans, lentils, whole grains, and low-fat or fat-free milks or yogurts.

Shorter Distance Nutrition

Shorter distance runners should follow general healthy eating guidelines, being sure to fuel adequately during the day so as not to run out of steam during a run. For example, if they plan to run before dinner, skipping lunch or having just a salad with chicken will probably not cut it, as it is too low in calories and carbs. They need to be sure to include some source of carbohydrates at the meal prior to the run, such as fruit, yogurt, and whole grain bread. Water is the best choice for hydration; sports drinks are usually not necessary unless you are going to sweat profusely for more than an hour.

Longer Distance Nutrition

Long distance runners should also be sure to follow general healthy eating guidelines but have additional diet considerations to keep in mind to perform their best. They will need to have a higher percentage of their daily calories, around 60 to 65%, from carbohydrates. For good nutrition, most of the carbs should come from fruits, vegetables, beans and lentils, whole grains, and low-fat or fat-free milks or yogurts. On training run days, runners should eat high-carb foods throughout the day and plenty of water. Inadequate hydration can lead to early fatigue and a disappointing training session. Long distance runners should be sure to regularly include foods high in iron in their diet as well; inadequate iron intake can lead to anemia (decreases the body’s ability to transport oxygen to tissues and remove carbon dioxide) increased heart rate (the heart has to work a lot harder to get adequate oxygen to their tissues), shortness of breath, and early fatigue. Female runners are especially susceptible to anemia, due to menstrual losses and diets that are often lower in iron content. High iron plant foods include black beans, kidney beans, lentils, soybeans, tofu, iron fortified hot and cold cereals, and spinach. Animal foods high in iron include dark meat poultry and beef. If eating beef, it is best to choose the leaner varieties such as loin, round, tenderloin (removing any visible fat), or 98% lean ground beef, which are lower in saturated fat than some other cuts.

Eating Before the Race

There is a lot of talk about carb-loading for runners. For people who run 5K and 10K races, there is really no need to carb load. Being well-trained, eating a balanced healthy diet that includes carbs the day before and morning of the race, and being well-hydrated is all that is needed diet-wise. For longer-distance runners, carb-loading is important. Proper carb-loading involves more than eating a lot of carbs the night before the race; ideally it happens over several days prior to the race along with a decrease in training. This allows the muscles to store extra carbohydrates, in the form of glycogen, for sustained energy. Even so, glycogen will get used up before the end of the race, which could result in a poor race performance or even not being able to finish. To combat this, runners need to carry some sources of easily digested carbs (which can include sports beans or gels) for a quick source of energy to keep them going. It is important to try out these products long before the day of the race to be sure the specific product is well-tolerated. Sports drinks are available on the race route and provide some carbohydrates, but most runners would not be able to consume enough to provide adequate carbohydrates to sustain their energy; the main purpose of sports drinks is hydration. The products formulated specifically for sustaining energy are a much more concentrated source of carbohydrate.

Runners should ultimately focus on following general healthy eating guidelines, adjusting carb intake as needed for length of runs, and staying hydrated.