On Your Mark Nutrition

Nutritional Articles Written by Katie Mark

Guest Articles


6 Traits to Look for in a Sports nutritionist

May 15, 2018

Sports nutrition is an art and a science. Investing in a high-quality nutritionist gets you more individualization, which accomplishes more for an athlete’s short- and long-term health and performance. As a sports nutritionist, athlete, and soon-to-be registered dietitian (RD), I’m sick of hearing “food is fuel” and other weak, outdated, and general sports nutrition advice.

If you are a pro athlete or team looking for a high-value nutritionist or a coach looking to outsource nutritional programming, then this article is for you.

First and foremost, I’m brutally honest in this article because I genuinely want to enhance the sports nutrition field. Therefore, it was very difficult to remain brief. I’m not trying to bash the field of RDs (licensed nutrition professionals). They are considered the “experts in food and nutrition,” but they’re not necessarily the experts in sports nutrition (as I explain below).

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Budgeting for omega-3 supplements:

what sports teams should know

Omega-3s are riding an alpha wave of hype. In the sports world, the use of omega-3s as a nutraceutical for repetitive head trauma and concussions is gaining momentum. This escalated demand, combined with a minimal consumption of fish and multiple studies reporting alarming omega-3 deficiencies among athletes and the general population, creates a perfect storm for supplement companies to swoop in and take advantage by marketing high-priced omega-3s.

Unfortunately, there’s confusion over which omega-3 product to purchase, which results in many puzzled looks when facing an overwhelming selection of omega-3 supplements in the vitamin aisle. Additionally, most supplement dosages don’t even match the research, and this makes efficacy highly questionable. After all, who wants to gulp down 10 fish oil pills each day?

While everyone is so concerned with omega-3 supplementation due to omega-3 deficiencies and the consequences of those deficiencies, very little attention is being given to the molecular carrier of the omega-3. This carrier heavily influences bioavailability, retention in the body, and subsequent efficacy in improving omega-3 deficiency to obtain desirable health outcomes. If the goal is a quick and efficient recovery from DHA deficiency, then the different forms of DHA supplementation must be considered.

This perfect storm of formula problems suggests omega-3 supplements are overpriced and overhyped. If you’re looking for more value than the nonchalant “just take an omega-3 supplement,” this article will tell you how to find a valuable source of omega-3s to better exploit their nutritional properties.


Boosting the Athletic Brain - From Nerve Cells to the Grey Matter

September 16, 2017

In the last minute of Super Bowl XLIX, the Seahawks were down by four and had the ball at the Patriots’ 1-yard line. Seahawks player Ricardo Lockette should have received the ball, but Patriots cornerback Malcolm Butler intercepted the pass from quarterback Russell Wilson, resulting in the Patriots winning the game, 28-24.

Does this make you wonder where an athlete’s catch originates, from the body or the brain? Lockette’s intention may have been there, but not the sharpness needed to physically execute the “challenge” received by the brain.

Is reaction time coachable or trainable? How much an athlete’s psychological efficacy—and the amount they can control—contributes to reaction time performance is unknown. Remove psychological factors and improving reaction time may depend on improving physiology—using nutrition to enhance neuronal speed.


The Ultimate Guide to Probiotics for Sport

August 2, 2017

Probiotic supplementation is a functional and practical nutritional strategy that powers an athlete's health for optimal performance and protects an athlete's future. The latest research suggests most health problems start in the gut. Therefore, gut microbiota is targeted as a potential therapeutic source for treatment of certain diseases.

Diet has the greatest impact on gut microbiota composition. Yet, many athletes' guts are currently a breeding ground for bad bacteria. Meal plans that enhance gut health look great on paper, but let's be real--athletes are not following that meal plan daily and probiotic-rich foods may be neither effective nor practical to consume every day.

In this article, I'll discuss why Olympians, recreational athletes, and those simply participating in physical activity need probiotics as an insurance policy for exercise, health, and longevity.


Superior Gut Health Translates to Athletic Power

June 14, 2017

An athlete's power traditionally develops from physical training. Power output is critical for success in sport, but power becomes more selective at the highest level, depending on an athlete's ability and training. If all things are equal physically, what is the key ingredient that will separate athletes at the top of elite sport?

The gut microbiome.

The gut is another route to increase horsepower. Optimizing gut microbiota means increasing the quality and diversity of the microbiota, which can increase the power of overall health. This power output propels an athlete to the top of the game via stronger immunity, lower inflammation, enhanced nutrient metabolism, and resilient brain function and behavior.

While beetroto juice may make the difference between gold and silver, the gut microbiome can determine whether an athlete makes it to the starting line. In this article, I'll explain how the gut is an athlete's control center for optimizing their power potential and why this offers the best chance of athletic success.


Can Citrulline Really Enhance Athletic Performance?

April 29, 2017

L-citrulline, a non-protein amino acid, is made by the body and used as a supplement for exercise performance because of cardiovascular effects optimizing blood flow. In the body, citrulline is converted to L-arginine (another amino acid), which produces nitric oxide (NO), a small molecule that dilates blood vessels to allow working muscle to receive more oxygen and nutrients, and remove metabolic waste. This optimized blood flow may help performance and accelerate recovery.


Athletes and Inflammation: When Is It Too Much?

August 31, 2016

The gut is an often overlooked part of the body that regulates inflammation. Athletes training with heavy loads are at an increased risk for infection, which requires them to pay greater attention to nutritional strategies used to mediate inflammation. This recovery should include probiotics, which have demonstrated to be a promising nutritional intervention to control and alleviate inflammation.

Before reading this blog, check out Immunity and Worldwide Competition because it explains how probiotics strengthen immunity and gut health, which will help you understand this blog's discussion of probiotics and inflammation.

In this blog, we will explain:

  • The process of inflammation

  • The association between exercise and inflammation

  • How probiotics regulate inflammation

  • Probiotics and their effect on exercise-induced airway inflammation and infection

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Immunity and Worldwide Competition

August 4, 2016

Our immunity is often a forgotten part of our nutrition plan for optimal recovery. Intense exercise weakens our immunity because of the impact on our gut - an organ that is 70% of our immune system. A weakened gut leads to an open window for opportunistic, bad bacteria to invade and cause infection. This susceptibility can disrupt training - which can decrease sport performance - or require withdrawal from a competition.

Fortunately, good gut microbiota can help make sure your hours of investment in training are worthwhile. Some gut microbes work with our gut and immune cells to take care of disturbances to immunity that result from high levels of physical and environmental stress.

In this blog, we'll discuss:

  • The relationship between immunity, the gut and microbiota

  • How probiotics strengthen immunity

  • The negative effects of intense exercise on our gut

  • The effects of probiotic supplementation in athletes

Athletes undergoing endurance training balance a fine line between enhancing health through exercise and hurting it. Exercise places physical stress on the gut, which lowers immunity. This is inevitable, but probiotics may be a simple nutritional intervention to fight the stress.

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A Nutritional Intervention for Performance

June 7, 2016

Probiotics are touted for strengthening immunity and maintaining a healthy gut, but one of the less emphasized health benefits is their positive impact on nutrition. Athletes are prone to flirting with certain nutrient deficiencies because of exercise demands and - sometimes - less than optimal nutrient intake. Research suggests taking probiotics is an attractive dietary intervention to optimize nutritional intake.

Gut bacteria receive their nutrition for energy and growth from our intake of carbohydrate, protein and fat. While breaking down food, bacteria release different by-products that subsequently impact our health and metabolism - most importantly, short-chain fatty acids (SCFAs). Here we provide the evidence-based research on probiotics and how they impact our digestion and absorption of nutrients and how SCFAs enhance our health.

  • Synthesize some B vitamins and vitamin K

  • Increase absorption of calcium, iron and vitamin D

  • Alleviate symptoms of lactose intolerance

  • Enhance dietary nitrate conversion to the vasodilator nitric oxide (e.g., beetroot juice)

  • Increase antioxidant activity

  • Lower cholesterol


5 Irrefutable Reasons Why Tufts School of Nutrition Was the Right Choice

May 3, 2016

The Friedman School of Nutrition Science and Policy at Tufts University is one-of-a-kind. Friedman is the only graduate school entirely devoted to nutrition in the United States. The school unites biomedical, social, political and behavioral scientists to provide a comprehensive approach to all things nutrition: education, research and community service. The collaboration of internationally renowned faculty and graduate students solidifies Tufts as a leading institution in the mission to improve the nutrition status of the United States and the world.

So who would say “no” to an acceptance letter from Tufts?