New Guidelines set to prepare athletes for the heat challenges of the 2020 Tokyo Olympic Games

Monash University researchers reveal nutrition and hydration management strategies for Olympic athletes to tackle heat-induced gastrointestinal issues that can be crippling to performance.

It is predicted that the Games of the XXXII Olympiad will present temperatures in excess of 30°C, accompanied by soaring humidity levels. One of the greatest challenges that athletes will face associated with these conditions is exertional-heat stress.

According to Advanced Accredited Sports Dietitian Dr Ricardo Costa, Monash University’s Department of Nutrition, Dietetics and Food, exertional heat-stress is a key factor for the development and magnitude of exercise-induced gastrointestinal syndrome and its associated performance debilitating gastrointestinal symptoms.

Dr Costa explained that “athletes competing in these types of environments are far more likely to experience exercise-induced gastrointestinal syndrome compared to cooler environments”.

The development of this syndrome is nothing to be sneezed at, particularly when it comes to competing at the top level - the Olympics. It can result in complications ranging from minor inconvenience (e.g. diarrhea and vomiting) to those requiring medical intervention [1-3]. 

High profile examples of exercise-induced gastrointestinal syndrome outcomes in recent Olympic Games include Paula Radcliffe's inability to finish the marathon at the 2014 Athens Olympics, where the temperature soared to 35°C with a humidity level of 31%. After the marathon Radcliffe described experiencing abdominal cramping, bloating and the urge to defecate [4].

For the very first time, Dr Costa and his team at Monash have established a set of recommendations to assist athletes in preparing for Tokyo 2020. As the world leaders in exercise gastroenterology pathophysiology, methodology, and translational practice the team were asked to undertake their review of the mechanisms causing the syndrome to manifest in the heat and provide guidelines, recently published in the journal Temperature.

From their review, Dr Costa explained that “heat exposure during exercise exacerbates the primary causes of exercise-associated gastrointestinal syndrome (splanchnic hypoperfusion and sympathetic drive), and subsequently the secondary outcomes (intestinal injury, hyperperfusion, reduced gut function, malabsorption, and systemic endotoxaemia and cytokine responses), compared with exercising in mild conditions”.  These symptoms can cause great discomfort and substantially impact an athlete's performance.

The good news is that the review identified clear interventions that can be used by athletes, coaches and medical staff to manage exercise-induced gastrointestinal syndrome at the Tokyo Olympics.

Prior to any individualized intervention being designed, Dr Costa urges that a “tailored gastrointestinal-assessment be undertaken as the essential first line of action to identify the causes of an athlete’s gastrointestinal issues in response to exertional-heat stress.” Once identified, the most appropriate prevention and management strategies can be applied. It is important to note that there is no one size fits all approach.

In terms of guidelines, the research identified that the management of exacerbation factors e.g. internal and external cooling strategies, maintenance of euhydration using cool fluids, consuming tolerable amounts of carbohydrate during exercise, and short-term dietary FODMAP restriction, are promising strategies to moderate alterations in gastrointestinal integrity and function, and associated symptoms, in response to exertional-heat stress.
The research also identified that gluten-free diets in non-coeliac athletes and dietary supplementations (e.g. probiotics, amino acids, bovine colostrum, antioxidants, and/or curcumin) provide no substantial benefits when included as part of an athletes strategy.

More information:
Dr Ricardo Costa is an Advanced Accredited Sports Dietitian and researcher at the Department of Nutrition, Dietetics and Food at Monash University. Ricardo’s research and practise focuses on Sports Medicine, Exercise Physiology, Sports Dietetics with a specific focus on exercise gastroenterology pathophysiology, methodology, and translational practice. Click here to access Ricardo’s research profile.

You can follow Monash Nutrition on Twitter via @MonashNutrition and the Monash Nutrition and Exercise Clinic via @MonashNutrExer.

The research team educate and train sport and exercise professionals on assessment technique and perform assessment through their online course (https://www.futurelearn.com/courses/fam-exercise-gut ) and Monash University’s BASE Nutrition and Exercise Clinic (https://www.monash.edu/medicine/base/about/clinics/nutrition-exercise-clinic).

Publication information
Ricardo J.S. Costa, Stephanie K. Gaskell Alan McCubbin & Rhiannon Snipe. Exertional-heat stress associated gastrointestinal perturbations during Olympic sports: Management strategies for athletes preparing and competing in the 2020 Tokyo Olympic Games. Temperature. 2019; DOI: 10.1080/23328940.2019.1597676

Click here to access the publication.

Image credit: Jacek-dylag on Unsplash

References

  1. Costa RJS, Snipe R, Camões-Costa V, Scheer BV, Murray A. The impact of gastrointestinal symptoms and dermatological injuries on nutritional intake and hydration status during ultramarathon events. Sports Med- Open. 2016;2(16):1-14.
  2. Gill SK, Hankey J, Wright A, Marczak S, Hemming K, Allerton DM, Ansley-Robson P, Costa RJS. The impact of a 24-hour ultra-marathon on circulatory endotoxin and cytokine profile. Int J Sports Med. 2015;36:688-695.
  3. Gill SK, Teixeira A, Rama L, Rosado F, Hankey J, Scheer V, Hemmings K, Ansley-Robson P, Costa RJS. Circulatory endotoxin concentration and cytokine profile in response to exertional heat stress during a multi-stage ultra-marathon competition. Exerc Immunol Rev. 2015;21:114-128.
  4. https://www.theguardian.com/sport/london-2012-olympics-blog/2012/mar/21/50-stunning-moments-paula-radcliffe

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