Personalized hydration strategies play a key role in optimizing the performance and safety of athletes during sporting activities. Clinicians should be aware of the many physiological, behavioral, logistical and psychological issues that determine both the athlete’s fluid needs during sport and his/her opportunity to address them; these are often specific to the environment, the event and the individual athlete. In this paper we address the major considerations for assessing hydration status in athletes and practical solutions to overcome obstacles of a given sport. Based on these solutions, practitioners can better advise athletes to develop practices that optimize hydration for their sports.

Environmental Health Perspectives is an Open Access journal published by the National Institute of Environmental Health Sciences. Environmental Health Perspectives is an Open Access journal published by the National Institute of Environmental Health Sciences.

Context: : No evidence-based recommendation exists regarding how far clinicians should insert a rectal thermistor to obtain the most valid estimate of core temperature. Knowing the validity of temperatures at different rectal depths has implications for exertional heat-stroke (EHS) management. Objective: : To determine whether rectal temperature (Trec) taken at 4 cm, 10 cm, or 15 cm from the anal sphincter provides the most valid estimate of core temperature (as determined by esophageal temperature [Teso]) during similar stressors an athlete with EHS may experience. Design: : Cross-sectional study. Setting: : Laboratory. Patients or Other Participants: : Seventeen individuals (14 men, 3 women: age = 23 ± 2 years, mass = 79.7 ± 12.4 kg, height = 177.8 ± 9.8 cm, body fat = 9.4% ± 4.1%, body surface area = 1.97 ± 0.19 m2). Intervention(s): : Rectal temperatures taken at 4 cm, 10 cm, and 15 cm from the anal sphincter were compared with Teso during a 10-minute rest period; exercise until the participant's Teso reached 39.5°C; cold-water immersion (∼10°C) until all temperatures were ≤38°C; and a 30-minute postimmersion recovery period. The Teso and Trec were compared every minute during rest and recovery. Because exercise and cooling times varied, we compared temperatures at 10% intervals of total exercise and cooling durations for these periods. Main Outcome Measure(s): : The Teso and Trec were used to calculate bias (ie, the difference in temperatures between sites). Results: : Rectal depth affected bias (F2,24 = 6.8, P = .008). Bias at 4 cm (0.85°C ± 0.78°C) was higher than at 15 cm (0.65°C ± 0.68°C, P < .05) but not higher than at 10 cm (0.75°C ± 0.76°C, P > .05). Bias varied over time (F2,34 = 79.5, P < .001). Bias during rest (0.42°C ± 0.27°C), exercise (0.23°C ± 0.53°C), and recovery (0.65°C ± 0.35°C) was less than during cooling (1.72°C ± 0.65°C, P < .05). Bias during exercise was less than during postimmersion recovery (0.65°C ± 0.35°C, P < .05). Conclusions: : When EHS is suspected, clinicians should insert the flexible rectal thermistor to 15 cm (6 in) because it is the most valid depth. The low level of bias during exercise suggests Trec is valid for diagnosing hyperthermia. Rectal temperature is a better indicator of pelvic organ temperature during cold-water immersion than is Teso.

Objective: The Sport Mental Health Assessment Tool 1 (SMHAT-1) was introduced as a critical component to the athlete health evaluation. However, the effectiveness of the initial triage step questionnaire (Athlete Psychological Strain Questionnaire (APSQ)) has yet to be analysed within a National Olympic and Paralympic Committee delegation. This study evaluated the ability of the APSQ to identify athletes at risk for mental health concerns. Methods: Athletes completed the APSQ and all subsequent screening questionnaires of the SMHAT-1 as part of their Tokyo and Beijing Olympic and Paralympic Games health history screening. Each questionnaire was scored according to published guidelines, and the false-negative rate (FNR) for the APSQ identifying athletes that were positively screened on the subsequent questionnaires was computed. Results: 1066 athletes from 51 different Olympic and Paralympic and Summer and Winter sports completed the SMHAT-1. The FNRs for all athletes who were positively screened on a subsequent questionnaire with an APSQ score of <17 ranged from 4.8% to 66.7%. The global FNR for being positively screened on any questionnaire was 67.5%. Female, Paralympic and Winter athletes scored higher on one or more questionnaires compared with male, Olympic and Summer athletes, respectively (p<0.05). Conclusion: Due to the high FNR of the APSQ detecting a potential mental health concern, we recommend athletes complete the APSQ and all subsequent questionnaires of the SMHAT-1 rather than using only the APSQ as an initial screening test.

Adams, WM, Ferraro, EM, Huggins, RA, and Casa, DJ. Influence of body mass loss on changes in heart rate during exercise in the heat: A systematic review. J Strength Cond Res 28(8): 2380–2389, 2014—The purpose of this review was to compare the changes in heart rate (HR) for every 1% change in body mass loss (ΔBML) in individuals while exercising in the heat. PubMed, SPORTDiscus, ERIC, CINAHL, and Scopus were searched from the earliest entry to February 2013 using the search terms dehydration, heart rate, and exercise in various combinations. Original research articles that met the following criteria were included: (a) valid measure of HR, (b) exercise in the heat (>26.5° C [79.7 °F]), (c) the level of dehydration reached at least 2%, (d) a between-group comparison (a euhydrated group or a graded dehydration protocol) was evident, and (e) for rehydration protocols, only oral rehydration was considered for inclusion. Twenty articles were included in the final analysis. Mean values and SDs for HR and percentage of body mass loss immediately after exercise were used for this review. The mean change in HR for every 1% ΔBML was 3 b·min−1. In trials where subjects arrived euhydrated and hypohydrated, the mean change in HR for every 1% ΔBML was 3 and 3 b·min—1, respectively. Fixed intensity and variable intensity trials exhibited a mean HR change of 4 and 1 b·min−1, respectively. Exercising in the heat while hypohydrated (≥2%) resulted in an increased HR after exercise. This increase in HR for every 1% ΔBML exacerbates cardiovascular strain in exercising individuals, thus causing decrements in performance. It should be encouraged that individuals should maintain an adequate level of hydration to maximize performance, especially in the heat.