Debunking Current Running Nutrition Fads

Of all the areas I know that I need to keep evolving, it’s my running nutrition. Of course, I’m slammed in the face daily with a new trend that’s going to change everything, which only adds to the confusion of what’s right, wrong and a waste of time.

Which is why I was thrilled when Marni Sumbal came out with Essential Sports Nutrition. Not only does she have alphabet soup behind her name MS, RD, CSSD, LD/N, but she actually practices what she preaches through Ironman racing and coaching!

I was lucky to meet Marni through Oakley over 5 years ago and have been blown away by her since then, which is why I asked her to come address some of the big myths and fads I see wrecking a lot of training!

Working out on an empty stomach?

The primary science behind fasting relates to its metabolic effects. Fasting before exercise (as in working out first thing in the morning without eating beforehand) may promote better fat burning because pre-workout carb consumption causes insulin to be released from the pancreas – reducing fat oxidation.

Thus, exercisers who voluntarily choose not to eat before a workout may help to train the muscles to more readily use fat as a substrate – thus burning more fat during the given workout. However, consuming carbohydrate before workout has consistently been shown to enhance performance despite increasing insulin levels and reducing fat oxidation.

What’s the best running nutrition option?

While it’s easy to workout on an empty stomach, fasted workouts are not as glamorous as they appear to be. They may:

• impair the ability to use carbohydrate efficiently during long distance or high intensity exercise
• may increase the risk of illness
• reduce training intensity
• compromise sleep
• negatively affect mood
• increase risk for overeating later in the day
• compromise recovery

For the casual exerciser, you may not notice any negative effects of fasted workouts. If you are exercising for weight loss and health benefits, have a go at the occasional fasted workouts before a low intensity training session to see if it makes a positive impact on your health, fitness and dietary choices.

But for the athlete who is training for an event, as you balance work, family and training, optimizing fat oxidation will likely not make a substantial difference in your athletic performance.

Optimal sleep, healthy eating, proper hydration, good recovery and consistent training will give you more of a performance boost than the occasional fasted training session.

Far too many athletes and fitness enthusiasts have compromised health and performance at the expense of trying to become a better fat burner through fasted training.

By eating a well planned and balanced diet during the day, committing to consistent sleeping habits in the evening, optimizing recovery and fueling and hydrating appropriately before (and during and after) your workouts, you’ll be able to stay consistent with training/exercising so that you can create a body that is strong, fit, fueled and healthy.

Wondering what current nutrition fads are good or bad for your running? An R.D. and Ironman athlete is tackling 3 of the most common here! #sportsnutrition #running Click To Tweet

What about all this Low Carb High Fat Diet Stuff? Keto?

You probably know that one person who has succeeded on a low carb high fat (LCHF) diet and has raved about his/her success. On the surface, this type of diet sounds attractive, especially with success stories boasting about a drop in appetite, rapid weight loss and improved endurance/fitness.

But there are many individuals who have overhauled the diet only to disrupt or destroy metabolic and hormonal health. As a reminder, your health and fitness is influenced by much more than what is occurring inside of you on a cellular level.

A ketogenic diet:

• 75% of calories come from fats
• 20% from protein
• 5% from carbohydrates

Carbohydrates are restricted to less than 50g per day, which is ~1.5 tbsp honey and one five-inch sweet potato.

Under normal physiological conditions, glucose is the brain’s major energy source. Under ketosis, the body must find an alternative energy source to maintain normal brain cell metabolism. Fatty acids broken down in the liver produce ketones, which then travel to the brain to be used as the new fuel source. The ketogenic diet was originally developed as a drug-free way to treat epilepsy.

Although research on a HFLC diet has shown to improve fat oxidation on a cellular level, well-designed research studies and real-world applications on performance under ketosis is lacking. 

Drawbacks to a keto diet for runners?

A LCHF diet can support very easy training days and low intensity workouts, but ketosis is physically and mentally limiting during high intensity and prolonged exercise sessions, competition and peak season training.

Side effects can include:

• fatigue
• low motivation
• dizziness
• sleep problems
• depressed appetite
• sickness
• injury
• digestive issues
• depression

More serious implications include impaired metabolism, hypoglycemia, increased sickness/injury, hormonal disturbance, dehydration, disordered eating, nutrient deficiencies, reduced capacity to utilize carbs, and central nervous system fatigue.

Despite strong evidence that a ketogenic diet can advance weight loss, long-term, there are no absolutes that this diet will help with weight maintenance, especially when dietary compliance may be challenging.

{Amanda’s Note: And there’s breaking research that this type of diet could shorten your lifespan!}

To ensure that your carb intake is benefiting your health and fitness, prioritize real-food carbohydrates such as whole grains, beans, lentils, fruit, vegetables, yogurt, milk and dried fruits.

Can you be successful as a vegetarian athlete?

An increasing number of health-conscious individuals are embracing a vegetarian-based diet and reducing some, if not all, animal products from the diet.

Regardless of the primary motive – weight maintenance/loss, religion, disease prevention, food safety concerns, animal rights, environment or improvement of overall health – a well-planned vegetarian diet can be appropriate for individuals during all life stages (ex. pregnancy, infancy and adulthood) as well as for athletes.

However, many people are are skeptical of switching to a plant-based diet due to the costs, fears of not consuming adequate daily protein and health issues related to nutrient deficiencies and a decline in muscle mass. Adopting a vegetarian/vegan diet won’t necessarily make you a better athlete, but a well-planned vegetarian diet can adequately meet the demands of your sport.

What to pay attention to with food planning?

Athletes who choose to eat a plant-based diet should place special emphasis on certain nutrients, like B12, vitamin D, Calcium, zinc and Iron, as well as on adequate calories, protein and healthy fats. Fortified foods may help fill-in any running nutrition gaps.

Interestingly, there are just as many unhealthy meat eaters as there are “unhealthy” vegetarians for a diet high sugar, fat and processed food is far from nutritious and performance enhancing.

As with any “diet,” do not assume that eliminating certain foods from will make you healthier, fitter, leaner or faster. Regardless of the diet name, any style of eating that eliminates entire food groups places an athlete at risk for health issues. Plant-based diets should be carefully planned with the help of a sport dietitian.

Other fads you have questions about? Let us know!

About Marni Sumbal

Marni Sumbal, MS, RD, CSSD is a nationally recognized sports dietitian and triathlon coach. Through her renowned successful private practice, Trimarni Coaching and Nutrition, she helps athletes from around the globe prepare physically and nutritionally for athletic events.

As an elite endurance triathlete who has completed 14 Ironman-distance triathlons (including qualifying six times for the Ironman World Championship in Kona, Hawaii) and placed overall female amateur at 2017 Ironman Chattanooga, she uses her real-life experiences and formal education to help educate, motivate and guide athletes to achieve athletic and nutritional excellence in training and on event day.

Her unique “health first, performance second” approach of applying sports and daily nutrition science to real-world setting has gained popularity with many age-group and professional athletes who want practical and realistic nutrition and training strategies when preparing for athletic events. You can contact Marni through her website, www.trimarnicoach.com.

Get more running nutrition advice in her new book Essentials of Sports Nutrition.

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