Active Voice: ACSM’s Partner, USMST, Shares First-Hand Insights on Heat Illness Issues during Competition at Recent World Cup Soccer – Part 2

By Gautam S. Nayak, M.D., FACC, FACP and Felipe Lobelo, M.D., Ph.D., FAHA

Viewpoints presented in SMB commentaries reflect opinions of the authors and do not necessarily reflect positions or policies of ACSM.

Gautam Nayak, M.D., is a cardiologist at Confluence Health in the Department of Cardiology, Wenatchee, Wash. He earned his M.D. degree from Tulane University in New Orleans, La., and completed training in both internal medicine and cardiology at the National Naval Medical Center in Bethesda, Md. Dr. Nayak is a playing member of the United States Medical Soccer Team (USMST), a member of their board of directors, and currently serves as president of USMST.

Felipe Lobelo, M.D., Ph.D., is a medical epidemiologist in the Division of Diabetes Translation at the National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention, Atlanta, Ga. He completed his medical training at the Rosario Medical School, Bogota, Columbia and his Ph.D. in epidemiology at the University of South Carolina in Columbia, S.C. As a member of ACSM, he currently chairs the Exercise is Medicine® (EIM) Pediatrics Committee. Dr. Lobelo also is a member of the USMST.

The USMST is an organization of physicians representing the U.S. in the Annual World Medical Football Championship. The USMST is committed to continuing medical education and community outreach. In 2013, launched a partnership with ACSM aimed at advancing EIM’s agenda to encourage healthcare providers to integrate exercise routinely in medical treatment plans for all patients. Here, in a final installment of this two part commentary Drs. Nayak and Lobelo share their expertise on the environmental challenges that facing athletes who recently competed at the FIFA and the World Medical Soccer Championships in Brazil. For further information, click here for Part 1.


In our previous installment, we provided some background on heat illness and introduced some key physiologic concepts that can help in recognizing the clinical manifestations of exertional hyperthermia. With this in mind, we can translate the physiology into a simple clinical approach centered on prevention and early treatment.

Exercise-associated muscle cramps (EAMC) or heat cramps occur following prolonged strenuous exercise. These often-excruciating cramps (just ask LeBron James!) typically occur in the legs, arms or abdomen, with spasms lasting 1-3 minutes - but may repeat for hours! Typically, EAMC is related to a sodium-water imbalance, where sodium losses through sweat are not adequately replaced or where fluid replacement has occurred solely through ingesting with hypotonic fluids like water. Treatment includes rest, prolonged stretching, and oral sodium chloride (NaCl) ingestion in fluids or foods. Prevention efforts involve maintaining a fluid and salt balance, which can be highly variable from athlete to athlete. These measures also can help prevent more severe manifestations of heat illness including heat exhaustion and exertional heat stroke, where core temperatures rise and impact organ function significantly. In this more extreme situation, early recognition, removal from the environment, and rapid cooling can be life-saving.

The biggest risk factors for heat-related illness include higher intensity exercise with cumulative heat exposure, age over 40, a body mass index over 27, dehydration, lack of acclimatization, poor fitness, alcohol use, use of heavy sports equipment, and certain medications (antidepressants, antihypertensives/diuretics, and antihistamines). While these risk factors raise the index of suspicion for heat illness, it is critical that preventive measures be implemented in higher risk settings, including acclimatization (minimum of three days), frequent breaks in activity, hydration, recovery, and scaling back when the environmental conditions call for it.

So with this knowledge in tow, how did the U.S. Medical Soccer Team fare in the equatorial climate of Natal during this year’s World Medical Football Championship? We were certainly set up for heat illness as we tend to be older than other national medical teams (average age 42) and despite our year-round efforts, maintaining ideal aerobic fitness and body composition is just as much a challenge for us as it is for our patients. In addition, we certainly had no time to acclimate given our work schedules. Well, our results on the pitch notwithstanding (a record of two wins, one draw and three defeats after an unlucky group stage draw, with the champion and runner up from last year), we’re happy to report no issues with significant heat-related illness. What struck us was the variability in everyone’s approach to prevention. Some stuck with simple water (each day, taking two liters per hour of activity plus an extra liter when temperature exceeded 25 °C) and salt (replenished as 0.5 g per hour of sweating). Others chose sports drinks or sports electrolyte solutions, a few swore by beer, and many chose the ever-prevalent Brazilian coconut water. This lines up with the literature, which has shown significant variability in what works best for fluid and electrolyte replacement. Playing six full soccer matches in seven days was no easy task, and though we encountered some physical injuries, the heat was not a factor given some of these simple precautions. In addition, water breaks were instituted in most games by officials’ judgment based on weather conditions – this option was also available for the first time at the FIFA World Cup games. This contingency really helped and is easy to replicate locally.

As soccer players, for us it was amazing to experience Brazil during the World Cup and to challenge ourselves physically on the pitch in a tropical environment. As physicians, our time in Brazil gave us a tremendous opportunity to appreciate the challenges involved in preventing and recognizing heat-related illness. We recommend that everyone review these excellent and freely available resources that we mentioned in Part 1 of this commentary. Collectively, these resources provide comprehensive recommendations on how we can prevent and manage this important issue in sports medicine.