Sports Nutrition: #ScienceNotOpinion

by Nancy Clark MS RD CSSD


Running performance starts with fueling, not training! The best way to fuel to be a better runner seems to be a debatable topic these days. To keep on top of the science regarding food, exercise & performance, I look to SCAN, the Sports & Cardiovascular Nutrition practice group of the Academy of Nutrition and Dietetics (AND). Here are some tidbits of information from this year's 35th annual meeting in Keystone CO, May 2018 (#SCANSymposium)

• In your search for sports nutrition information, Leslie Bonci RD CSSD wants you to find #ScienceNotOpinion  and #FactsOverFallacy. Here's some of what science supports:

—Exercising in a fasted stated leads to muscle breakdown. Think twice before eating nothing before your morning run.

—The keto diet does not enhance performance, but rather leads to a down-regulation of the enzymes needed by carbohydrates to fuel a surge or a winning sprint to the finish line.

—Whole30 and Intermittent Fasting are just two more fads to add to the list of unsuccessful diets. You never want to embark upon a diet you won't maintain for the reset of your life. Otherwise, diet backlash (binge eating, weight gain) takes it toll. Learn how to eat smarter, not diet harder!

 —Carb-phobia refuses to go away, despite the plethora of research supporting the performance benefits of a carb-based sports diet. #Don'tDreadTheBread.

• Omega-3 fats (DHA, EPA) found in oily fish (salmon, tuna, mackerel) are related to brain health.

Animal research (rats, mice) suggests giving intravenous DHA within an hour after brain or spinal cord injury contributes to better outcomes regarding recovery. Would the same help athletes? Could DHA help with reducing the damage done by brain injuries? According to Michael Lewis MD, athletes, war fighters, and others at high risk for getting concussed should consider taking 3,000 mg. EPA + DHA per day as a protective strategy.

Omega-3s can also help treat depression, and that might help reduce suicides. Among soldiers with adequate levels of omega-3, the suicide-rate was 62% lower than soldiers with low blood levels of DHA.

• Should runners take anti-oxidant supplements?

Likely not, according to exercise physiologist Scott Powers PhD of the University of Florida in Gainesville. The body has a natural balance of pro-oxidants and anti-oxidants. An imbalance can lead to muscular fatigue and molecular damage. Anti-oxidant supplements can down-regulate the body's natural production of anti-oxidants, and that can blunt the training response. Runners can ingest a performance enhancing balance of anti-oxidants (including vitamins C & E, zinc, carotenoids, and polyphenols) via all sorts of colorful fruits and vegetables: blueberries, strawberries, tart cherry juice, grape juice, broccoli, spinach, carrots....

• The Academy of Nutrition and Dietetics, along with the American College of Sports Medicine and Dietitians of Canada, have created guidelines on nutrition for athletes. ( http://ow.ly/HpQm30jXJaf)

But what about nutrition for fitness exercisers and weekend warriors? If that's you, exercise physiologist Asker Jeukendrup PhD of www.mysportscience.com suggests you match your nutritional guidelines to your athletic goals. That is, are you running for fitness? to be an elite athlete? or just to invest in have fun?

When it comes to fueling during extended exercise, Jeukendrup stated the recommendations are similar for both serious runners and less fit joggers: For running that lasts from 60 to 90 minutes, you want to maintain high energy by consuming from 30 to 60 grams of carbohydrate (120 to 240 calories) per hour of exercise (this includes what you eat right before you start to run). If you are doing extended training for more than two hours, you might want to target a bit more, up to 60 to 90 grams carh (240 to 360 calories) per hour, depending on body size (more) and intensity of exercise (less). Start at the low end of the range and train your gut (the gut is trainable!) to tolerate the amount of fuel that maintains high energy, enhances your performance, and boosts your enjoyment.

• An estimated 35 million Americans are older than 65. By 2030, 70 million Americans will exceed the age of 85.

Unfortunately, as we age, we lose muscle strength. That loss is associated with frailty and falls. Because the daily diet of an estimated 25% to 40% of older people lacks adequate protein, muscle loss gets exacerbated.

Research suggests that older people, including runners, should increase their protein intake to 1.4 g to 1.6 g/kg per day, and up to 40 grams after hard exercise. Exercise physiologist Robert Murray PhD of www.sportsscienceinsights.com reports this could help boost the muscle-building response to exercise. If you are an older runner who weighs 150 pounds (68 kg), this means. 95 to 110 gram protein per day. That's about 25 grams, four times a day—much more than in a bowl of oatmeal or a handful of nuts!

• The health risks of yoyo dieting are more harmful than the (short-lived) benefits of weight loss.

Julie Duffy Dillon RD of the Love, Food podcast reminds us that weight cycling (yoyo dieting) contributes to malnutrition, muscle loss, reduced metabolic rate, and feelings of deprivation. The binge-eating that occurs upon "blowing the diet" is linked to fat gain, inflammation, elevated blood pressure, and insulin resistance—to say nothing about disordered eating. Dieting is the #1 predictor of who will develop an eating disorder.

• According to sports dietitian Nanna Meyer PhD RD of the University of Colorado in Colorado Springs, climate change is here.

It's time for all athletes to think more about how we can be good Food Citizens and take better care of the earth that we enjoy. This could be by eating locally grown foods, choosing more plant foods, buying sustainably farmed fish, using fewer plastic water bottles, eating less food in wrappers, and buying from local farmers. We want to eat with integrity and respect for the planet!


Nancy Clark, MS, RD counsels both casual and competitive athletes at her office in Newton, MA (617-795-1875). Her best selling Sports Nutrition Guidebook and Food Guide for Marathoners offer additional information. They are available at www.NancyClarkRD.com. Her online workshop, www.NutritionSportsExerciseCEUs.com is popular with health professionals and athletes alike.

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