Nutrition on the Run

Abstract

Approximately 7.6 million high school students in the United States participate in sports. Although most sport-related injuries in adolescents are considered minor emergencies, life-threatening illnesses or injuries may occur, such as sudden cardiac arrest, heat stroke, status asthmaticus and exercise-induced asthma, catastrophic brain injuries, cervical spine injuries, heat- and cold-related illness, blunt chest/abdominal injuries, and extremity fractures resulting in compartment syndrome. Emergency preparedness in athletics involves the identification of and planning for medical services to promote the safety of the athlete, to limit injury, and to provide medical care at the site of practice or competition. Several national organizations have published guidelines for emergency preparedness in school-based athletics. Our article reviews guidelines for emergency preparedness put forth by the Sideline Preparedness collaboration (comprised of 6 major professional associations, including the American Academy of Family Physicians, American Academy of Orthopedic Surgeons, American College of Sports Medicine, American Medical Society for Sports Medicine, American Orthopaedic Society for Sports Medicine, and American Osteopathic Academy of Sports Medicine), the National Athletic Trainers' Association, the American Academy of Pediatrics' Committee on School Health, and the American Heart Association. Additionally, we review published data examining compliance of US high schools with these recommendations for emergency preparedness in school-based athletics, determine deficiencies, and provide recommendations for improvement based on these deficiencies.     

The discriminative power of the Interval Shuttle Run Test and the Maximal Multistage Shuttle Run Test for playing level of soccer

AIM: The purpose of this study was to examine the discriminative power of the recently developed Interval Shuttle Run Test (ISRT) and the widely used Maximal Multistage 20 m Shuttle Run Test (MMSRT) for soccer players at different levels of competition. The main difference between the tests is that the exercise mode of the ISRT is not continuous but intermittent. Instead of 60 s of running per stage in the MMSRT, 30 s of running are alternated with 15 s of walking, twice per stage. METHODS: Comparative study: within a 2-week period, 81 male soccer players at the Dutch premier league professional, premier league and 3rd division amateur levels performed the ISRT and the MMSRT. The total number of runs was scored for both tests. RESULTS: Only the ISRT distinguished between levels of competition. In general, the ISRT correlated moderately with the MMSRT for players of different levels of competition (rP: 0.52-0.83). CONCLUSIONS: In contrast to the MMSRT, the ISRT shows discriminative power for soccer players at different levels of competition supporting the validity of the ISRT for measuring endurance in a more soccer-specific way. As a result of the intermittent character of the ISRT the energetics of the ISRT and the MMSRT are not closely related.     

早期肠道营养与静脉营养对大鼠烧伤后代谢的影响

目的 设计肠道和静脉营养的烧伤大鼠模型,比较两种营养途径对烧伤后早期代谢的影响。方法 Ｗｉｓｔａｒ大鼠分为早期肠道营养组（ＴＥＮ组）,正常对照组。ＴＥＮ组和ＴＰＮ组均为３０％Ⅲ度烧伤,液体复苏,分别灌喂和静脉输注营养液,两组给予热量和氮量相同。观察６小时至３天的体重、静息能量消耗（ＲＥＥ）、尿氮、尿儿茶酚胺和血浆胰岛素、胰高血糖素、皮质醇变化。结果 ＴＰＮ组ＲＥＥ在烧伤后７２小时明显高于Ｃ组入ＴＥ     

獭兔的营养研究现状

獭兔的主要经济价值在于其毛皮，兼顾产肉。但近年来獭兔的皮毛品质有一定程度的下降，这既与其品种有关，又和营养供应有很大的关系。影响獭兔的生长发育、毛皮品质、繁殖和养殖经济效益的关键是饲料的营养水平。本文对獭兔的蛋白质和氨基酸、能量、粗纤维、脂肪、微量元素及维生素等营养研究现状进行了叙述，希望能对我国的獭兔生产提供一定的参考。     

Nutrition for the pediatric athlete

A paucity of literature exists with regard to research on nutrition for the pediatric athlete. This lack of research makes the development of specific nutritional recommendations for young athletes problematic. This issue is made difficult by the macro- and micronutrient intake required for growth and development in conjunction with that required for sports. Exogenous carbohydrate drinks could be considered for the young athlete engaged in both endurance exercise and high-intensity exercise. Monitoring of the energy intake during resistance training in the pediatric athlete needs to be considered, as there is evidence to suggest that energy deficits may occur. If decrements in exercise performance are noted, then serum ferritin and hemoglobin concentrations should be monitored, as nonanemic iron deficiency is prevalent in the pediatric athlete. The pediatric athlete exercising in the heat is susceptible to voluntary dehydration and evidence exists to suggest that a carbohydrate-electrolyte drink will abolish this phenomenon.     

Nutrition of the older athlete

Nutritional needs and dietary goals of the older athlete involve meeting basic physiologic requirements of aging and exercise, promoting weight control, and incorporating guidelines for reducing the risk of chronic disease. Conservative dietary approaches to weight loss in the obese patient and a high-carbohydrate diet for maximum exercise performance are sound approaches, although diets often need to be individualized. Recent dietary recommendations to reduce fat and increase fiber can be applied without risk of compromising nutritional status for most patients. Guidance away from extremes in caloric restriction and in the distribution of calories may help to promote health and the maintenance of exercise activities. Although requirements for certain micronutrients are affected by aging, vitamin and mineral supplements are unlikely to be necessary for healthy adults and should meet basic criteria for safety if they are prescribed. Diet sources of calcium may require attention, although iron requirements are reduced among postmenopausal women when compared with younger athletes. Adequate fluid replacement is essential for athletes of all ages. For the older athlete who is competing in high-intensity endurance exercise, evidence for the usefulness of 4% to 10% carbohydrate-containing sports drinks exists. Little evidence supports the use of ergogenic aids, such as supplements and unusual food products. Resources and personalized guidance from a registered dietitian can be helpful for many older athletes.     

Those Viral Skin Infections Can Run Wild

Society's acceptance of alcohol complicates the problems of athletes and coaches. The panel discusses the social as well as the physiological implications of alcohol use and abuse.     

Run performance of middle-aged and young adult runners in the heat

The aging process may impair exercise tolerance in the heat. It is not clear whether this impairment is partly due to a reduction in aerobic capacity. To compare the exercise performance and thermoregulatory responses of middle-aged and young adults with similar aerobic capacities and training statuses, 7 middle-aged (54±2 years; 58±4 ml·kg?-?1·min?-?1) and 7 young (28±1 years; 61±5?ml·kg?-?1·min?-?1) male competitive endurance runners underwent 2 10-km self-paced and 2 fixed-workload (90% of race speed) runs until fatigue on a treadmill in hot (40°C) and moderate (20°C) environments on separate days. The runners' total time, average speed, rectal temperature, heat storage rate, physiological strain index, sweat rate, sweat sensitivity, number of heat-activated sweat glands and sweat rate per sweat gland were measured or calculated. Body fat, body surface area, body surface area per body mass, training volume and VO2max were similar between the 2 groups. No differences were observed in total time (59±3; 49±3; 27±2; 54±5 min in the middle-aged and 60±2; 49±3; 27±2; 51±4 min in the young group), average speed, rectal temperature, heat storage rate, physiological strain index, sweat rate (17±7; 15±3; 23±7; 13±2 g.m?-?2.min?-?1 in the middle-aged and 20±5; 14±4; 22±5; 15±4 g.m?-?2.min?-?1 in the young group) or sweat sensitivity between age groups (p>0.05) in any trial. The number of heat-activated sweat glands (88±14; 80±18; 90±16; 66±14 cm?-?2 in the middle-aged and 43±10; 32±10; 37±11; 31±11 cm?-?2 in the young group) was higher, and the sweat rate per sweat gland was smaller, in the middle-aged than the young group (p<0.05) in all of the trials. We conclude that running performance and body thermoregulation are similar between young and middle-aged runners with similar aerobic capacities and training statuses under hot and moderate conditions in self-paced and fixed-intensity runs. The decrease observed in the sweat rate per sweat gland in middle-aged men was compensated for by a higher number of heat-activated sweat glands.     

Nutrition update for the ultraendurance athlete

Participation in ultraendurance events has been increasing. Appropriate nutrition in training and fueling while racing within the confines of gastrointestinal tolerability is essential for optimal performance. Unfortunately, there has been a paucity of studies looking at this special population of athletes. Recent field studies have helped to clarify appropriate fluid intake and dispel the myth that moderate dehydration while racing is detrimental. Additional current nutrition research has looked at the role of carbohydrate manipulation during training and its effect on macronutrient metabolism, as well as of the benefits of the coingestion of multiple types of carbohydrates for race fueling. The use of caffeine and sodium ingestion while racing is common with ultraendurance athletes, but more research is needed on their effect on performance. This article will provide the clinician and the athlete with the latest nutritional information for the ultraendurance athlete.     

10000米耐力跑对腰椎稳定肌预期与补偿姿势调节的影响

目的:探讨急性全身性耐力运动对身体平衡控制能力、背伸肌最大收缩能力以及腰椎稳定肌预期姿势调节(APAs)和补偿姿势调节(CPAs)的影响。方法:17名男性警察学院大学生参与该实验。受试者先进行最大背伸肌力测试、闭目单足站立试验和快速举臂试验,而后进行10000米耐力跑,并在跑后即刻重复上述3个项目的测试,检测耐力跑前后受试者的背伸肌最大肌力和闭目单足站立时间,并在快速举臂试验中同步采集腰部竖脊肌和多裂肌的表面肌电信号(sEMG),计算竖脊肌和多裂肌的激活时间以及APAs和CPAs阶段的反应强度。结果:(1)10000米耐力跑前后受试者背伸肌力无明显变化,但耐力跑后闭目单足站立时间大幅度缩短;(2)内部姿势干扰条件下,相较10000米耐力跑前,耐力跑后受试者腰部竖脊肌的激活时间显著提前,而腰部多裂肌在APAs阶段的反应强度显著减小;10000米耐力跑后腰部竖脊肌和多裂肌在CPAs阶段的反应强度均显著减小。结论:10000米耐力跑未能造成背伸肌群疲劳,但会影响机体维持静态平衡的能力;10000米耐力跑影响内部姿势干扰条件下中枢神经系统对腰椎稳定肌的前馈控制策略,通过提早收缩腰部竖脊肌来补偿腰部多裂肌预激活强度的减小。     

Nutrition in the exercising elderly.

When making nutrition recommendations to the exercising elderly population, four important areas should be taken into consideration: (1) the changing needs that occur with age; (2) the changing needs that occur with exercise; (3) the presence of any chronic illnesses or diseases; and (4) whether one is exercising for fitness, recreation, or competition. For the most part, these four areas have been researched separately, and recommendations for elderly athletes need to be synthesized from this information. The nutrients for which food consumption is often inadequate and has the largest impact on the exercising elderly population include vitamin B6, vitamin B12, calcium, and vitamin D. The exercising elderly population needs to be aware of their bodies changing needs with exercise and should focus on maintaining energy balance while selecting a wide variety of foods high in complex carbohydrates. When adequate dietary intakes cannot be obtained, supplementation with a multivitamin of no more than 100% of the RDA is recommended.