FUEL UP FOR DISTANCE RUNNING

Runners have a unique set of dietary requirements that are vastly different from that of a strength, power or physique athlete. As endurance athletes – those whose continuous activity ranges in length of time from 30 minutes to 4 hours – energy requirements are very different. In this article, we’ll take a look at the unique requirements of runners and provide ways to customize a diet plan specific to a runner’s needs. 

Endurance athletes, like distance runners, require a tremendous amount of energy (calories) to sustain lengthy training sessions. Ultra-endurance athletes can use up to 6,000-8,000 calories per day during training season. Inadequate dietary support may result in dehydration, chronic fatigue, muscle loss and injury. In addition, training energy and performance ability will decline.

Based on gender, age and activity level, there are simple formulas on running websites and in sports nutrition books that can be used to calculate Resting Energy Expenditure (REE) for athletes in any sport. REE can then be used along with an Activity Factor Range to determine daily energy needs. Go to MarathonGuide.com to find a caloric calculator for runners.

Ultimately, physical factors can be used to determine if more or less energy is required. Any negative symptoms such as dehydration, ongoing fatigue, decreased performance or increased injuries could mean daily caloric needs are not being met. Customize your calorie needs as necessary based on these factors. 

Runners and athletes in general require more dietary protein than their sedentary counterparts. This is thought to be due to the needs of tissue repair and an increase in branched-chain amino acid use as auxiliary fuel. Protein intake for athletes generally ranges from 1.5 – 2.0 g/kg of body weight, with endurance athletes on the low end. However, some endurance athletes may train and perform better with more calories coming from protein and may wish to shift to the higher end of this range. Most important when it comes to dietary protein is choosing high-quality sources – those with high biological values and listed as complete proteins. This will ensure regeneration of tissue damaged during training. 

Complete and high-quality proteins are most typically found in the form of animal protein. Eggs, for instance, contain all essential amino acids, while grain and vegetable sources fall short and must be combined throughout the day to deliver the necessary amino acids. Quality sources also include protein shakes containing whey, casein and/or soy, poultry, meat and fish, milk, yogurt and cottage cheese. Vegetarian options include the combinations of peanut butter and whole wheat and beans and rice. 

Carbohydrates are a crucial energy source for runners, and they also work to metabolize fats for energy. If the muscles and liver get depleted of their carbohydrate (glycogen) stores, an athlete will experience extreme fatigue (perhaps dizziness and nausea) as blood sugar drops to a very low level. Athletes require a constant replenishment of carbohydrates since the body can only store so much in the liver and muscles. 

After about 20 minutes of continuous exercise, the body starts pulling blood glucose for energy. Glycogen levels continue to deplete with continued exercise, and liver glycogen is used around 1½ hours into exercise. Glycogen levels are typically depleted after 3 hours of continuous training. 

To support the endurance athlete, carbohydrate recommendations are listed at 5-10 g/kg of bodyweight. This creates quite a large range. An alternative method is to determine 50-65 percent of total caloric needs and divide by 4 to get daily carbohydrate gram requirements. Based on a 2,000 calorie diet, if carbohydrate intake were 60 percent, 1,200 calories would come from carbohydrates, which would equate to 300g daily.

To support training and overall health, carbohydrate sources should be healthy. In general, choose 100 percent whole grains and starches and avoid processed and refined sources. These “white” carbs have been linked to obesity, inflammation, heart disease, diabetes type 2 and many other chronic diseases. Simple carbs should be chosen during and after training only to quickly help replenish glycogen stores.

Distance athlete Esther Hare weighs in on her own dietary habits as an Olympic and Half-Ironman Triathlete: “I’m not a believer in carb loading…. What’s more important is what’s in your body a couple of hours before and then during a long distance race, and even more importantly, what’s been in your body consistently for the last few months of training.”

Pre- and post-training and pre-competition carbohydrate loading phases require higher and more frequent carbohydrate intake. Research shows that consuming carbohydrates 2 hours prior to an endurance event greatly increases performance by sparing muscle and liver glycogen for a longer duration. A 2002 study showed that running capacity was increased by 9 percent in those who consumed carbohydrates versus those in a fasted state. 

 

In addition, “fast” carbs from simple sugars are beneficial to consume during and after training and competition. These can come in the form of drinks, gels or bars. In addition to the pre-exercise meal, intra-training carbohydrate consumption offers an additional 6.9 percent increase in performance, cited the same 2002 study. Athletes must carefully observe and learn how much and which forms of carbohydrates offer them the best performance benefits while minimizing negative side effects. Too many carbohydrates can result in an upset stomach, diarrhea and cramping. A general range of carbohydrate needs during exercise for endurance athletes is 1.0 – 1.1 g per minute of activity. 

Post-exercise carbohydrates should be consumed as soon as possible – preferably within 15 to 30 minutes – to replenish glycogen stores. This will help prepare for the next training session, minimizing fatigue and performance impairment. Whole foods, juices and low-fat dairy are good post-exercise choices. 

Fat should not be forgotten about, as fat is a great source of long-term energy for both exercise and everyday activities. After protein and carbohydrate percentages have been determined, the final macronutrient of a well-rounded endurance athlete is fat. Fat should be consumed with every meal with the possible exception of pre- and post- training or competition. Fat prior to training may cause the feeling of a full stomach since dietary fat delays gastric emptying. This may be uncomfortable to some people. Fat after training would also slow the digestion rate, and thus, the body’s speed at which glycogen stores may be replenished. 

Hare is also an amateur figure competitor, so her diet is structured for both performance and aesthetics. She follows a vegetarian diet of 45-50 percent carbohydrates that consist of low-glycemic, high-fiber options balanced with 25-30g protein per meal and healthy fats such as extra virgin olive oil and avocado. Says Hare of her diet, “Getting my protein right is key … to making sure I stay lean, but also to keep my blood sugar constant to avoid any sugar cravings.” MS&F