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Browsing by Author "Stearns, Rebecca L."

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    Nutritional, Physiological and Perceptual Responses During a Summer Ultra-Endurance Cycling Event
    Armstrong, Lawrence E.; Casa, Douglas J.; Emmanuel, Holly; Ganio, Matthew S.; Klau, Jennifer F.; Lee, Elaine C.; Maresh, Carl M.; McDermott, Brendon P.; Stearns, Rebecca L.; Vingren, Jakob L.; Wingo, Jonathan E.; Williamson, Keith H.; Yamamoto, Linda M.; University of Alabama Tuscaloosa
    Despite the rapid growth of mass-participation road cycling, little is known about the dietary, metabolic and behavioral responses of ultra-endurance cyclists. This investigation describes physiological responses, perceptual ratings, energy balance, and macronutrient intake of 42 men (mean ± SD; age, 38±6 y; height, 179.7±7.1 cm; body mass, 85.85±14.79 kg) and 6 women (age, 41±4 y; height, 168.0±2.9 cm; body mass, 67.32±7.21 kg) during a summer 164-km road cycling event. Measurements were recorded one day before, and on Event Day (10.5 h) at the start (0 km), at two aid stations (52 km and 97 km), and at the finish line (164 km). Ambient temperature was >39.0°C during the final 2 h of exercise. Mean finish times for men (9.1±1.2 h) and women (9.0±0.2 h) were similar, as were mean gastrointestinal temperature [TGI], four hydration biomarkers, and five perceptual (e.g., thermal, thirst, pain) ratings. Male cyclists consumed enough fluids on Event Day (5.91±2.38 L; 49% water) to maintain body mass within 0.76 kg, start to finish, despite a sweat loss of 1.13±0.54 L·h-1 and calculated energy expenditure of 3,115 Kcal·10.5h-1 . However, men voluntarily underconsumed food energy (deficit of 2,594 Kcal, 10.9 MJ), and specific macronutrients (carbohydrates, 106±48 g; protein, 8 ± 7 g; and sodium, 852 ± 531 mg) between 0530 and 1400 h. Also, a few men exhibited extreme final values (i.e., urine specific gravity of 1.035 to 1.038, n=5; body mass loss >4 kg, n=2; TGI, 39.4 and 40.2). We concluded that these findings provide information regarding energy consumption, macronutrient intake, hydration status and the physiological stresses that are unique to ultra-endurance exercise in a hot environment.
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    Practical Hydration Solutions for Sports
    (MDPI, 2019) Belval, Luke N.; Hosokawa, Yuri; Casa, Douglas J.; Adams, William M.; Armstrong, Lawrence E.; Baker, Lindsay B.; Burke, Louise; Cheuvront, Samuel; Chiampas, George; Gonzalez-Alonso, Jose; Huggins, Robert A.; Kavouras, Stavros A.; Lee, Elaine C.; McDermott, Brendon P.; Miller, Kevin; Schlader, Zachary; Sims, Stacy; Stearns, Rebecca L.; Troyanos, Chris; Wingo, Jonathan; University of Connecticut; Waseda University; University of North Carolina; University of North Carolina Greensboro; Australian Institute of Sport; Brunel University; Arizona State University; Arizona State University-Downtown Phoenix; University of Arkansas Fayetteville; Central Michigan University; State University of New York (SUNY) Buffalo; University of Waikato; University of Alabama Tuscaloosa
    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.