RESUMO
Overexposure to ultraviolet radiation (UVR) from the sun is associated with deleterious health effects including, but not limited to, increased risk of skin cancers. Military personnel and those who participate in outdoor exercise or sports represent two potential populations at elevated risk of negative health consequences of UVR exposure due to large amounts of time spent outdoors, often in harsh UVR environments. Despite exposure to high and/or frequent doses of UVR in recreational and tactical athletes, adequate sun-protection practices are often disregarded or not well understood by many within these at-risk populations, resulting in heightened risk of negative UVR effects. The focus of this review is to examine the available literature regarding UVR exposure, risk of adverse health effects of UVR exposure, and sun protection practices in outdoor exercisers, athletes, and military personnel.
Assuntos
Atletas , Militares , Exposição à Radiação , Raios Ultravioleta/efeitos adversos , Exercício Físico , Humanos , Queimadura Solar/epidemiologia , Protetores SolaresRESUMO
BACKGROUND: The beverage hydration index (BHI) is a composite measure of fluid balance after consuming a test beverage relative to water. BHI is a relatively new measure that has been explored in young, but not yet older, adults. OBJECTIVE: The aim of this study was to investigate potential differences in BHI between euhydrated younger and older adults after drinking 4 different commercial beverages. We hypothesized that 1) older subjects would remain in positive fluid balance longer than young subjects after ingestion of each test beverage due to decreased urinary excretion rates, 2) glucose (glu)- and amino acid (AA)-based hydration beverages with sodium would have a BHI greater than water in both groups, and 3) the traditional 2-h postingestion BHI may be inappropriate for older adults. METHODS: On 5 separate visits, 12 young (23 ± 3 yr, 7 M/5F) and 12 older (67 ± 6 yr, 5 M/7F) subjects consumed 1 L of distilled water, G-20 (6% CHO, 20 mmol/L Na+), G-45 (2.5% CHO, 45 mmol/L Na+), AA-30 (5 AAs, 30 mmol/L Na+), or AA-60 (8 AAs, 60 mmol/L Na+) over 30 min. Blood and urine samples were collected before ingestion and at 0, 60, 120, 180, and 240 min postingestion with additional venous blood sampling at 5, 10, 15, and 30 min postingestion. RESULTS: In young subjects, BHI increased with increasing beverage Na+ concentration, and AA-60 had the highest BHI (AA-60 = 1.24 ± 0.10 compared with water = 1.00, P = 0.01). For older subjects, BHI was highest in AA-30 (AA-30; 1.20 ± 0.13 compared with water, P < 0.01) and was still in flux beyond 2 h in AA-60 (P < 0.05). CONCLUSIONS: Beverage Na+ content progressively increased BHI in young adults independent of glucose or AA content. For older adults, the AA-30 beverage had the highest BHI. A 4-h BHI may be more appropriate for older adults due to attenuated urine excretion rates. This trial was registered at clinicaltrials.gov as NCT03559101.