Training for endurance races?

A UCHealth clinical and sports nutritionist and an experienced marathon runner and triathlete shares insight into proper nutrition
Aug. 3, 2016

As a certified clinical and sports dietitian with UCHealth’s Center for Diabetes and Nutrition at Poudre Valley Hospital in Fort Collins and at Poudre Valley Medical Fitness in Windsor, Kissane focuses on the importance of proper nutrition as she continues to prepare for other triathlons and the 2017 Boston Marathon.

Katie Kissane has completed five marathons and several Olympic-distance triathlons, most recently winning the Steamboat Marathon in Colorado with a time of 3 hours, 10 minutes and 40 seconds.

She shared her knowledge and highlighted key things to consider when preparing for his or her next big race or just beginning in the competitive endurance-racing world.

Katie has completed five marathons and several Olympic-distance triathlons, most recently winning the Steamboat Marathon in Colorado with a time of 3 hours, 10 minutes and 40 seconds.

Hydrate. Dehydration can be detrimental to performance. A loss of about 5 percent of body weight can decrease the capacity for work by 30 percent. The consequences of dehydration include early fatigue, cardiovascular stress, increased risk of heat illness and decreased performance. The goal is to lose no more than 2 percent of body weight from water.

Begin exercise well hydrated, replace sweat loss by drinking during exercise and rehydrate after activity to replace any water weight you lost during exercise. Consider sports drinks or electrolyte drinks for exercise lasting longer than 60 minutes.  Otherwise, water is a great choice.

During exercise lasting fewer than 60 minutes, any electrolytes lost in sweat can be easily replenished with foods consumed during the day. As exercise duration and intensity increase, the loss of electrolytes in sweat can be substantial, especially in hot, humid environments. This loss of electrolytes can lead to decreases in performance, muscle cramping and even hyponatremia (low levels of sodium in the blood). Electrolytes such as sodium and potassium are important because they help maintain a healthy fluid balance within the body, contribute to muscle contraction and are vital in nerve impulse conduction.

After exercise make sure to replace fluid and sodium losses with watery foods that contain salt, such as soups. Potassium losses can be replaced by eating fruits and vegetables.

Fuel properly. In order to get the most out of training, make sure to fuel properly. For long-duration or high-intensity workouts, make sure to fuel before, during and after the workout. It’s hard to get the full benefit from an exercise session when not fueled properly.

Practice your nutrition.  Don’t wait until race day to try a nutrition strategy. This should be done in the months and weeks leading up to race day. During long runs practice hydration and fuel strategies. Find out what type of sports drinks and fuel will be provided during the race, and try using those. Another option is to carry fuel and hydration, such as gels, gummies, jelly beans, sport bars, sports drinks or energy.

Consider nutrition periodization. Many training plans involve a training cycle or training periodization approach, and nutrition should be the same way. During nutrition periodization the macronutrient intake fluctuates depending on the goal of the training cycle. There may be additional nutrition strategies that can be implemented during periodization for specific goals such as improving fat burning or building muscle. For instance, one might limit carbohydrates during longer, lower-intensity training in order to train the body to be more efficient at burning fat during exercise.

Don’t fill up on junk food. It can be tempting to eat whatever sounds good because a lot of calories are being burned during training sessions. Endurance exercise is demanding on the body, and nutrient requirements are greater for individuals participating in long-duration exercise or training several hours a week. This is why it is so important to eat foods that support training. This includes adequate amounts of protein, fat, carbohydrates, vitamins, minerals and antioxidants. Make sure the nutrition plan includes adequate protein from lean meats, legumes, nuts and dairy. It is recommended that athletes consume five to nine servings of fruits and vegetables daily. Good carbohydrate sources include whole grains and starchy vegetables.

Eat real food as much as possible. Supplements are meant to support, not replace, a healthy diet. Many athletes pay a lot of money for supplements that don’t work or only provide a minimal benefit, but they have not addressed their diet. This is like paying money to have a car repainted while neglecting the basic vehicle maintenance. Proper nutrition is fundamental to athletic performance, and there is no nutritional supplement that can replace the benefits of food.

Carbohydrates do matter. This is especially true during high-intensity training. There has been some limited research on low-carbohydrate diets in athletes as a means of increasing fat burning during exercise. This seems to be most beneficial during long-duration, low-intensity training. Once the intensity of exercise increases, the low-carbohydrate diets hinder performance. This is because carbohydrates are a rapid fuel source, and it takes longer to break down fat for fuel. Adequate carbohydrates are necessary to fuel the working muscles.

Get help with your nutrition. There is a lot of misinformation on the internet about nutrition for endurance training. Because nutrition is such a big part of athletic performance, it is wise to consult with a professional. Consider working with a dietitian who specializes in sports nutrition for endurance athletes.

Address stomach problems. Many endurance athletes complain about gastrointestinal (GI) upset during training. There is nothing worse than having runner’s trots during a training session or race. Blood flow to the GI tract is impaired during exercise, and it is believe this contributes to GI symptoms. The gut is sensitive to water and nutrient intake during exercise. It is advised to limit high-fiber foods within the day or days leading up to a competition. Other strategies include avoiding milk products that contain lactose before training or a competition, as even mild lactose intolerance can cause GI distress. It is possible to “train the gut” by trying different nutrition strategies during training and to become accustomed to fluid and food ingestion during exercise. The gut is adaptable, and this is another good reason to incorporate nutrition training as an important part of a training plan.

Katie Kissane is board certified as a specialist in sports dietetics and has been a runner for the past 20 years, starting her running career in middle school at the age of 13. She ran both cross-country and track in college at the University of Colorado while completing her undergraduate degree in kinesiology. She continued to run and started training for triathlons while completing her master’s degree in human nutrition at Colorado State University. She is currently competing for the Harvest Moon half-ironman distance triathlon in Boulder this September. Following that race she plans to transition back to marathon training, with the goal of competing in the Boston Marathon in April of 2017.

If you are interested in learning more about nutrition for endurance exercise and how Katie can help you with your performance nutrition goals, you can set up an appointment with her at Poudre Valley Medical Fitness by calling 970.674.6500 or email Katie to set up an appointment at

About the author

UCHealth is an innovative, nonprofit health system that delivers the highest quality medical care with an excellent patient experience. With 24,000 employees, UCHealth includes 12 acute-care full-service hospitals and hundreds of physicians across Colorado, southern Wyoming and western Nebraska. With University of Colorado Hospital on the Anschutz Medical Campus as its academic anchor and the only adult academic medical center in the region, UCHealth pushes the boundaries of medicine, providing advanced treatments and clinical trials and improving health through innovation.