An unexpectedly high percentage of runners are vegetarians, or even vegans, though no one knows why for certain. It could be that some runners believe vegetarian diets are healthy (they are!) or a path to faster performances. Others might choose to lose weight or stay lean the vegetarian way, another proven method.

Runners also tend to support clean air, clean water, and healthy soil, and these priorities often lead to vegetarian practices. Still others oppose the killing of other sentient animals.

I was drawn to vegetarianism at age seventeen by many of the above factors, but mainly through the influence of my coach and mentor, John J. Kelley. Minutes after we finished long, sweltering summer runs, Kelley would grab his shovel and dig into his backyard compost pile and garden.

At first, as a new convert to cross-country running, I mainly wanted to get faster. I figured almost any exotic foods might help—yogurt, brewer’s yeast, wheat germ oil. When General Mills introduced a new whole-wheat cereal named Total, I was instantly hooked.

I couldn’t resist a food claiming to contain 100 percent of many vitamins and minerals. While others in my high school wolfed down pizza and burgers for lunch, I munched a container of dry Total with no milk, sugar, or other toppings. You won’t be surprised that no one ever asked to swap lunches with me.

In those early years, I knew little about the nutrition side of vegetarianism. Looking back I’m amazed that I survived. In fact, I ran my fastest times and won my biggest races, including the Boston Marathon, in those days. I’m sure my heavy training and laser-like motivation were bigger factors than my diet.

Still, the diet worked, and soon there were many magazines, books, and ultimately websites where I could learn more about vegetarianism. I’ve been well satisfied with my results and my personal health. I’ve also met a handful of other accomplished endurance athletes who have thrived on vegan and vegetarian diets.

  

Understand your vitamin B12 needs: A vitamin B12 deficiency can be a problem for vegetarians, since liver and other meats are the best sources. Yet I was not aware of a concern until I hit sixty. Suddenly I felt that I was more fatigued than I should be. From a laboratory blood test, I learned that I had grown deficient in vitamin B12, so I began getting monthly shots. Problem solved. A few years later, I switched to B12 pills (two thousand milligrams a day), and the good results continued.

  

Don’t sweat the protein: When I first switched to a vegetarian diet as a teenager, everyone warned that I would fail to get enough protein. The early books were full of exacting instructions on how to eat beans, corn, and other “complementary proteins” in the same meal to ensure maximum protein availability. Now we know that a narrow time window is not critical. If you consume a variety of protein foods across the day, you’ll do fine.

Of course, eggs and dairy products are excellent protein foods as well. In particular, modern nutrition studies have shown that regular egg consumption is not dangerous to the heart. I enjoy an ample vegetable omelet several times a week.

  

Ward off anemia: Vegetarian diets are often poor in heme iron, the most biologically active form of iron, found mainly in meats. While many vegetarian foods contain iron, it often isn’t readily available to the body tissues. One good trick: Cook with a cast iron pan. Some of the iron will be absorbed into your foods. Or combine foods rich in vitamin C—like fruits, for example—with iron-containing foods like soybeans, tofu, and fortified breakfast cereals. If necessary, use ferrous sulfate supplements.

  

Consume enough calories to support your running: Some vegetarian runners are such fastidious eaters that they don’t consume enough calories. This can spiral downward if you’re not careful. It could lead to illness and/or injury.

Try not to be overly restrictive about what you eat. Far better to consume a wide variety of foods, including some high-calorie foods like nuts, olive oil, avocados, and dark chocolate, which are full of healthy fats. Food is meant to sustain us and be enjoyable. Even vegan and vegetarian runners can eat many different foods.