In May 2013, I attended the American College of Sports Medicine's annual meeting in Indianapolis, along with over 6,000 exercise scientists, sports dietitians, physicians, and health professionals who gathered to share their research. Here are a few nutrition highlights:
Running on empty: While athletes engaged in endurance exercise should consume 30 grams carbohydrate per hour during 1 to 2 hours of exercise, and 60-90 g carb/h for exercise lasting more than 2.5 hours, some athletes prefer, because of intestinal issues, to refrain from consuming food and fluids before and during exercise. New research shows that for athletes who "train on empty" just rinsing their mouths with a sports drink can reduce the perception of fatigue and improve performance by 3%. So, the next time your young athlete's stomach can't handle anything and they are about to hit the wall, have them try swishing and spitting;
Power up: Strength and power athletes engaged in high intensity exercise (i.e., gymnastics, weight lifting, ice hockey) rely on carbohydrates for fuel. While they commonly eat plenty of protein, they often fail to consume adequate carbohydrates. Instead of supplements to enhance their energy, they should try eating more oatmeal, sweet potato, or brown rice.
Some popular sports supplements for strength/power athletes include creatine (for weight lifting and other repetitive high intensity exercise that lasts for less than 30 seconds) and beta-alanine and sodium bicarbonate (buffers that reduce fatigue associated with lactic acid build-up during 1 to 6 minutes of sprint-type exercise, including track and crew). Sodium bicarbonate is best tolerated when taken in capsule-form, not as baking soda.
Strength/power athletes who train intensely should be sure to drink enough water. Being dehydrated by 3% reduces muscle power and strength in the upper body by 7% and in the lower body by 19%. Don't underestimate the power of proper hydration!
Nothing beats beets: Could eating beets/drinking beet juice before daily training help athletes train harder and thereby compete better? Perhaps. Nitrate-rich beets, concentrate beetroot juice "shots", and other nitrate-rich foods (spinach, rhubarb, arugula) get 
converted into nitric oxide, which helps reduce the amount of oxygen needed during constant-work-rate exercise. Hence, for the same oxygen uptake, athletes who consume beet juice "shots" might be able to exercise harder. For example, a runner might improve by 5 seconds a mile.
Some athletes respond better to dietary nitrates than others. Perhaps the "strong responders" routinely eat very few fruits and veggies, hence have a low nitric oxide baseline. Consuming nitrates might contribute to a more dramatic response. Note: bacteria in the mouth help convert dietary nitrate into nitric oxide. Skip the mouthwash!
Gut check: Research continues to show the influence of bacteria and other microbes on health. The human body contains 10 times more microbial cells than human cells. About 2 to 6 pounds of these microbes live in the intestines, where they help digest food, synthesize vitamins, and strengthen the immune system. This gut ecosystem changes according to diet, use of antibiotics, heat stroke, and other factors (some known, some unknown). For example, the gut bacteria of obese children can differ from that of lean kids, just as the gut bacteria of gastric bypass clients can change after surgery. (Maybe this is one reason why bypass patients lose weight faster than predicted) Microbes might play also play a role in Alzheimer's disease, hyperactivity in kids, and heart disease, so take good care of your gut! This means enjoying fiber-rich fruits, vegetables, and whole grains (microbes like to eat fiber) as well as cultured foods (yogurt, kefir) and fermented foods (miso, Kimchi, tempeh, blue cheese). Probiotic supplements might also be helpful. For female athletes with PMS, taking probiotics for the seven days before the start of the menstrual period might reduce PMS symptoms, as well as the risk of diarrhea (a common problem at the time of the menstrual period).
Sleep less, weigh more. In the past 20 years, Americans have been sleeping less. This drop in sleep mirrors a rise in obesity. Sleep is restorative; the body needs sleep to maintain normal circadian rhythms. And with that, I say, good night.
Nancy Clark, MS RD CSSD is MomsTeam's sports nutrition expert, a Board Certified Specialist in Sports Dietetics and best-selling author. She counsels both fitness exercisers and competitive athletes in her private practice in the Boston-area. Her books, including Sports Nutrition Guidebook, Food Guide for Marathoners and Cyclist's Food Guide are available at www.nancyclarkrd.com and www.sportsnutritionworkshop.com.
Posted June 10, 2012
