Table 2.
Nutrition-related adverse outcomes in competitions and endurance and ultra-endurance sports, investigated in randomized clinical trials.
| Study | Objectives | Sample | Sporting Competition | Adverse Outcomes | Incidence | Causes | Conclusions |
|---|---|---|---|---|---|---|---|
| Armstrong et al. (2017) [40] | -To evaluate the state of cyclists who began the competition with normal plasma [Na+], but finished it with 130 mmol/L. -Comparison of the values of these cyclists with those of a control group of 31 normonatremic cyclists. |
33 M | Open-air cycling competition, “Hotter’N Hell Hundred” (164 km), USA. (2016) | EAH. | EAH: 2 cases (6%) | Recommendations about the total intake of liquids and the change in the concentration of [Na+] determined the development of this condition. | -Each athlete must develop their own personalized plan for water intake, which includes measures during training, such as the calculation of the rate of sweating. -The precision of this method depends on the coincidence in the field simulation, regarding the environmental conditions and the intensity of the exercise. |
| Cutrufello et al. (2016) [41] | -To examine the relationship between the density of the urine, the bioelectrical impedance, and the body mass, before and after a marathon. -To check the hypothesis regarding the loss of body mass and of total body water that marathon runners experience. |
35 athletes -10 F -25 M |
Marathon in the USA (2015) | Hydration state. | Hyperhydration: 22 cases (62.8%) | Lack of knowledge about hydration in this type of competition. | -The body mass values seem to reflect changes in hydration, but not when using the values of a single athlete. -The hydration regime before and after a marathon should be considered in future investigations, and the time of completion of the race should be compared with the bioelectrical impedance results. |
| Valentino et al. (2016) [42] | -To determine if DH (defined as body mass losses ≥3%) leads to critical changes in body temperature during an ultra-marathon of 161 km. -To check if the hydration state directly affects the body temperature. |
30 athletes -7 F -23 M |
WSER ultra-marathon (161 km), USA (2014) | Hydration state (Only 20 athletes managed to complete the race) |
DH: 10 cases (50%) GI illnesses: 5 cases (16.7%) |
The athletes who lost a higher percentage of body mass completed the race more quickly. | -The losses of body mass (3–4%) were not related to the state of HT. -To avoid losses of body mass ≥2% during such events, it is not necessary to achieve a state of hyperhydration since it does not prevent HT. |
| Knechtle et al. (2011) [43] | -To investigate the prevalence of EAH in athletes in ultra-endurance sports modalities. -Comparison of the prevalence of EAH in these athletes with that in marathon runners and Ironman triathletes. |
200 athletes | Ultra-endurance races in Switzerland (2007–2009): -Swimming marathon in open water -2 cycling marathons -2 running marathons, 1 race of 100 km |
EAH. | EAH: 12 cases (6%) | Consumption of alcohol and a high frequency of intake of liquid. | -The mean prevalence of EAH among the athletes studied was 6%. -The prevalence of EAH was higher than that found elsewhere for marathon, ultra-marathon, and Ironman competitors. |
M = male; F = female; GI: gastrointestinal; EAH: exercise-associated hyponatremia; EHS: heat stroke by exertion; DH: dehydration; HT: hypothermia.