Eating for the Endurance Athlete

Often during my early morning runs, I find myself contemplating the important things in life. How good I must look when I run, how delicious that bowl of lucky charms is going to taste for breakfast, should I wear pants or shorts today (the answer is always shorts), etc. Today I found my mind wandering to a different topic. As I prepare for another summer of competitive running and mountain biking, I thought back to the seasons where I performed best. What I discovered was pretty amazing. After my run, I looked back through my training logs. My volume and intensities rarely changed; however, my best seasons appeared to have one thing in common…a good “clean” diet. Now, this is a far cry from my current diet of PBR and pizza, gummy bears, and mountain dews but as I get older, I am starting to realize the importance of a clean diet for optimal training, performance, and recovery. My coach use to say to me, “When the fire is hot you can burn anything.” Apparently, he did not take into account an aging body and metabolism. We all know that training can only take you so far. It is the little things you do in addition to the training that can make the difference between mediocre results or a PR. Good sleep, a good massage therapist, and most importantly a proper diet.

I’ll be the first to admit it…I am an endurance junkie. To me, pure bliss is going on a 50-mile run in the Black Hills of South Dakota or redlining in a multi-stage mountain bike race. In a world where masculinity is defined by an incredible hulk like stature, rock hard abs, bulging biceps, and massive protein consumption, I’m the guy who wants to flutter like a leaf in the wind, be almost invisible when I turn sideways and eat copious amounts of carbohydrates…GASP!!! I want to train hard, race fast, and be well fueled before, during, and after to accomplish those objectives. In order do this it is crucial my diet is finely tuned for optimal endurance performance.

So what should a typical endurance athlete’s ideal diet look like? Let’s start with the backbone of most endurance athlete’s diet…the carbohydrate. Generally speaking, endurance athletes training 90 or more minutes a day should consume ~8-10g of carbohydrate per kg of body weight. This amount has been shown to adequately restore skeletal glycogen within 24 hours and is important when back to back days of intense cardiovascular sessions take place or during a period of heavy training volume. It is also important to note that high concentrations of muscle glycogen induce a protein sparing effect which has the potential to lead to faster recovery times. At first glance, it may appear the carbs are the only way to go for the endurance athlete to achieve optimal performance, but this may not be the case in all circumstances.

Fats, or lipids, if we want to feel better about the word, have a strong place in the endurance athlete’s diet. General recommendations for fat consumption are 20% of total daily caloric intake. Considering the caloric density of fat (vs. a carb) and the energy requirements of some endurance athlete’s (up to 5000 kcal/day) it makes sense to include fat to achieve a caloric balance without having to eat constantly throughout the day. This doesn’t mean you eat a Big Mac every day but instead get your fat calories from foods such as avocados and nuts. Research has shown that consuming up to 50% of calories from fat during periods of heavy endurance training did not affect plasma lipids or performance. An additional study demonstrated that trained runners consuming 38% of calories from fat in the presence of adequate caloric intake enhanced performance. In untrained men, a diet high in fat resulted in identical endurance performance improvements compared to a high carbohydrate diet. So you see fat isn’t that bad after all and compared to the limited ability of the body to store carbohydrate, fat stores are large and represent a vast fuel source for exercise.

This brings us to the hot macronutrient of the last decade…protein…an often-overlooked component of an endurance athlete’s diet. Compared to the general public an endurance athlete’s protein requirements are slightly higher. Research indicates that the protein needs of endurance athletes range from 0.8g– 1.4g per kg of body weight. It is thought that higher amounts of protein promote tissue repair and serves as a fuel source during exercise. Adding protein to a carbohydrate may also speed glycogen replenishment following hard training due to a greater insulin response following the exercise sessions. As you endurance junkies are feasting on your pre-race spaghetti dinner be sure to add a chicken breast or some meatballs…your body will thank you.

At the end of the day you’ll see there really is no “ideal” diet that applies to every endurance athlete out there to achieve optimal performance. The above recommendations are a place to start. Experience and experimenting with different diets and finding what foods and combinations of macronutrients produce the best results are the key to success. Just like you log your training; log your diet every day. There are many useful tools out there such as fitness pal that make this process painless. Go back from time to time and review what your diet was like previous to a record-breaking performance or great training cycle. Like many things in life, success is determined by repeating a process that works.


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