I've been a vegetarian for 14 years, just about my entire racing career. The past 3 years I've been completely vegan, which means I don't use any animal products whatsoever.
In parts 1 and 2 of this 3-part series on the vegetarian athlete, I focused generally on overall nutrition, and specifically on the macronutrients (protein, carbohydrates, and fat), and micronutrients