June: Juiced

   You are a science project. With every workout, you focus calculated efforts on improving your body, with the results revealed in the next workout, the next race. In all likelihood, running describes not just something you do, but someone you are. And for this reason, scientific experimentation carries on well after you've shed your running shoes for the day-in your diet, for example.

   Runners seize on food crazes with the same blind enthusiasm as anyone else and typically get the same disenchanting results. Yet how else do we learn? Carbohydrate loading before a distance race or workout undoubtedly forestalls bonking. Salty foods have long been proven to slow dehydration in hot weather. And no one needs to tell you that as your weekly mileage increases, so do your caloric needs. Hunger confronts a runner like a demanding but familiar dragon. It should remind you of the efficiency with which you burn fuel. It's okay to feed the dragon.

   So when does experimentation go too far? The human body suffers dietary nostrums with surprising forgiveness. Frankly, it's astonishing how we survive what we eat. It's likewise surprising how little it matters in athletic performance. Kenyan marathoners may have many secrets for why they consistently win, but their breakfasts won't reveal much. Over months and years we want to develop eating habits that better our abilities while also extending our lives. Unfortunately, no single regimen prevails. The best advice that nutritionists and sports physiologists collectively purvey is to eat a varied and balanced diet. Most of us don't consume enough fruits and vegetables. So eat your broccoli.

   With so little specific advice available, many runners experiment with the exploding stable of dietary supplements, some of which were purportedly formulated with running in mind. Approach these with skepticism. Only four supplements have demonstrated unqualified effectiveness by the National Institutes of Health: vitamin D and calcium for women at risk of osteoporosis, folate for pregnant women, and fish oil (with omega-3 fatty acids) for lowering cholesterol and blood pressure. Everything else is taken on faith - or because of the results you're actually getting. But bear in mind that the Food and Drug Administration has very little authority over the $21 billion supplements industry. Charlatans and snake-oil salesman are rife.

   Food crazes of any kind seduce runners with the same promise of training itself: a calculated, marginal benefit. Your bases are covered. Or perhaps it's just easier to buy something than to change something. Truth is, adding hill charges to your workouts or grabbing an extra hour of sleep will often do more for your performance than timing your protein intake or popping a magic pill. The key is to be aware when you're getting carried away with a dietary idea.

   In the meantime, be grateful for the ferocity of appetite that running brings. It's no secret that runners live life more fully than sedentary people. Hunger should be a vibrant signal of how rich your experience has become.