Energy balance and dietary habits of America's Cup sailors

This research, which was conducted with crew members of an America's Cup team, had the following objectives: (a) to assess energy expenditure and intake during training; (b) to evaluate the sailors' diet, and (c) to identify any dietary flaws to determine the appropriate intake of nutrients, correct possible dietary mistakes, and improve their food habits. Energy expenditure was estimated on 15 sailors using direct measurements (oxygen consumption) and a 3-day activity questionnaire. Oxygen consumption was measured on sailors during both on-water America's Cup sailing training and dry-land fitness training. Composition of the diet was estimated using a 3-day food record. Average daily energy expenditure of the sailors ranged from 14.95 to 24.4 MJ, depending on body mass and boat role, with the highest values found in grinders and mastmen. Daily energy intake ranged from 15.7 to 23.3 MJ (from +6% to -18% of energy expenditure). The contributions of carbohydrate, protein, and fat to total energy intake were 43%, 18%, and 39% respectively, values that are not in accord with the recommended guidelines for athletes. Our results show the importance of assessing energy balance and food habits for America's Cup sailors performing different roles. The practical outcome of this study was that the sailors were given dietary advice and prescribed a Mediterranean diet, explained in specific nutrition lectures.     

Anaerobic capacity, isometric endurance, and Laser sailing performance

Laser sailors have to tolerate fatiguing contractions of the lower-body muscles for prolonged periods. The aims of the present study were (1) to evaluate the difference between top-ranked and club sailors, in their capacity to resist fatigue during sustained isometric and maximal power exercise, and (2) to examine the relationships between the above parameters and performance on a Laser simulator and competitive racing performance according to the national ranking list. Eight Greek nationally ranked Laser sailors were compared with eight club sailors. Each sailor performed: (a) an effort to the limit of tolerance on the Laser simulator, (b) an effort to the limit of tolerance of isometric endurance for the right leg on an isokinetic dynamometer, and (c) a Wingate test of maximal lower-body anaerobic power on a cycle ergometer. In the nationally ranked sailors, isometric endurance time (mean 160 s, s = 50) and endurance time on the Laser simulator (1381 s, s = 1354) were significantly (P < 0.05) longer than in the club sailors (101 s, s = 29 and 565 s, s = 367, respectively), whereas the final minute heart rate (in both groups: 149 beats . min(-1), s = 22) and the mean arterial pressure (nationally ranked sailors: 129 mmHg, s = 16; club sailors: 120 mmHg, s = 21) on the Laser simulator were not different between groups. During the Wingate test, the nationally ranked sailors had a significantly lower index of fatigue (42%, s = 5) than the club sailors (49%, s = 6). Isometric endurance time was significantly correlated with the Wingate index of fatigue (r = -0.73; P < 0.001). The nationally ranked sailors' mean and maximal anaerobic powers were significantly correlated with their national ranking positions (r = -0.83 and -0.71, respectively). It is suggested that isometric endurance and anaerobic power are well-developed in Laser class sailors and may influence their sailing performance. Furthermore, compared with club sailors, the nationally ranked sailors are able to sustain the same intensity of lower-limb isometric contractions for much longer with similar cardiovascular responses.     

Nutrition for endurance sports: marathon, triathlon, and road cycling

Endurance sports are increasing in popularity and athletes at all levels are looking for ways to optimize their performance by training and nutrition. For endurance exercise lasting 30 min or more, the most likely contributors to fatigue are dehydration and carbohydrate depletion, whereas gastrointestinal problems, hyperthermia, and hyponatraemia can reduce endurance exercise performance and are potentially health threatening, especially in longer events (>4 h). Although high muscle glycogen concentrations at the start may be beneficial for endurance exercise, this does not necessarily have to be achieved by the traditional supercompensation protocol. An individualized nutritional strategy can be developed that aims to deliver carbohydrate to the working muscle at a rate that is dependent on the absolute exercise intensity as well as the duration of the event. Endurance athletes should attempt to minimize dehydration and limit body mass losses through sweating to 2-3% of body mass. Gastrointestinal problems occur frequently, especially in long-distance races. Problems seem to be highly individual and perhaps genetically determined but may also be related to the intake of highly concentrated carbohydrate solutions, hyperosmotic drinks, as well as the intake of fibre, fat, and protein. Hyponatraemia has occasionally been reported, especially among slower competitors with very high intakes of water or other low sodium drinks. Here I provide a comprehensive overview of recent research findings and suggest several new guidelines for the endurance athlete on the basis of this. These guidelines are more detailed and allow a more individualized approach.     

江苏省摔跤队膳食营养状况的调查与评价

研究目的:膳食营养是保证运动员营养素的需要和维持体能的最重要的物质基础,对训练起重要的保证作用,与膳食营养在竞技体育中重要位置不相适应的是运动员膳食的不平衡现象普遍存在,它长期影响训练的效果和训练后的恢复。本研究通过调查备战十运会的江苏省摔跤队的膳食状况,对其做出评估,为平衡膳食提供依据。研究方法:采用食物称重法,称量并记录每个运动员所吃主副食的熟重、剩余重量,计算出所吃食物生重。记录运动员饮水量及营养品服用量,用软件计算出各种营养素摄入量及食物构成。将计算结果与运动员每日膳食营养供给标准,食物摄入供给标准进行比较做出合理评价。研究结果:江苏省摔跤运动员三大营养素的摄入比例多不合理,碳水化合物78%不足,56%的运动员脂肪和蛋白质超过推荐标准。中餐、晚餐的能量摄入比例超标比例较高,早餐不足。运动员各种矿物质摄入都超过推荐值,运动员的维生素摄入相对不足,VA、VC、VB1、VPP不同程度地缺乏。运动员每日的摄入量变化很大,最大幅度可达到83%。运动员进食的多少与运动量、运动强度、饭菜的内容以及个人的喜好有很大的关系。     

Ramadan fasting and the goals of sports nutrition around exercise

Ramadan fasting, involving abstinence from fluid and food from sunrise to sundown, results in prolonged periods without nutrient intake and inflexibility with the timing of eating and drinking over the day. Dietary choices may also change due to special eating rituals. Although nutrition guidelines are specific to the sport, to the periodized training and competition calendar, and to the individual, many promote the consumption of carbohydrate and fluid before and during exercise, and consumption of protein, carbohydrate, and fluids soon after the session is completed. Failing to meet overall nutritional needs, or to provide specific nutritional support to a session of exercise, is likely to impair acute performance and reduce the effectiveness of training or recovery. Muslim athletes who fast during Ramadan should use overnight opportunities to consume foods and drinks that can supply the nutrients needed to promote performance, adaptation, and recovery in their sports. Because of the benefits of being able to consume at least some of these nutrients before, during or after an exercise session, the schedule of exercise should be shifted where possible to the beginning or end of the day, or during the evening when some nutritional support can be provided.     

New insights in professional horse racing; “in-race” heart rate data,elevated fracture risk,hydration, nutritional and lifestyle analysis of elite professional jockeys

Weight-making practices have been shown to impair musculoskeletal and physiological function of jockeys. This study investigated the “in-race” heart rate (HR) responses and hydration status during competitive racing, as well as selected physiological and lifestyle parameters of professional jockeys based in Hong Kong. “In-race” HR responses and early morning hydration status of 20 male jockeys were examined in hot and moderate climactic occasions. Additionally, bone mineral density (BMD), dietary intake and lifestyle choices were assessed. Osteopenia was observed in the calcanei of jockeys (left: 0.51 ± 0.06; right: 0.46 ± 0.12 g · cm^?2). Energy and protein intake were significantly lower on a race day compared to a non-race day (P < 0.05). “In-race” HR_max values were similar to those from VO_2max laboratory tests (186 ± 14 vs. 185 ± 8 bpm). Hypohydration was observed on both racing days. (USG: 1.0247 ± 0.006 and 1.0256 ± 0.0258 mg · L^?1 for hot and moderate conditions, respectively). Sauna usage (25.5%) and food restriction (20.4%) were the most common weight-making practices. Current lifestyle choices of jockeys result in suboptimal bone health, hydration status and nutritional intake, which can significantly enhance the fracture risk. Further research should develop exercise and nutrition guidelines for optimising their skeletal health.     

我国青少年蹦床运动员膳食营养调查研究

目的:了解青少年蹦床运动员膳食营养知识、膳食营养态度以及膳食营养行为等信息,进而改善其营养水平,为提高运动成绩服务。方法:以10-17岁青少年蹦床运动员为调查对象,设计蹦床运动员膳食营养知信行调查问卷,对运动员进行问卷调查。结果:青少年蹦床运动员膳食营养知识平均分为6. 5±1. 73分(不及格),知识短板主要是对食物中营养素的构成以及人体所需的能量物质来源等知识点的理解有偏差;膳食营养态度平均分为7.03±1.81分(良好),总体上膳食营养态度表现积极;膳食营养行为平均分为13. 43±3. 07分(及格),运动员的食物选择主要依靠心情或者胃口,营养素摄入不均衡,有一部分蹦床运动员不按照队里的规定购买或食用食物。结论:我国青少年蹦床运动员主要依靠教练或亲戚朋友获取营养知识,正确的饮食习惯有待加强,膳食营养行为需要合理监控。建议:开设相关营养课程,加强运动员对膳食营养重要意义的认知,配备专业的膳食营养师进行膳食营养搭配和监控。     

Yacht type and crew-specific differences in anthropometric, aerobic capacity, and muscle strength parameters among international Olympic class sailors

Physical fitness and muscular strength are important performance factors for Olympic class sailors, but the physical demands vary greatly between yacht classes, and limited information is available regarding the physical demands for the different crew positions. In the present paper, strength and aerobic capacity data from elite Olympic sailors are presented and compared with previous findings. Furthermore, a system for classification of Olympic class sailors is suggested. Peak aerobic capacity (peak oxygen uptake, VO(2peak)) and maximal isometric and isokinetic muscle strength of the knee extensors and flexors were assessed, together with the hamstring/quadriceps strength ratio (H/Q ratio). Peak aerobic capacity (ml O(2) . min(-1) . kg(-2/3)) was as follows: males - static hikers (n = 5) 215, s = 7; dynamic hikers (n = 8) 252, s = 17; trapezing helmsmen (n = 6) 234, s = 15; trapezing crew (n = 10) 239, s = 16; females - dynamic hikers (n = 6) 194, s = 16; trapezing crew (n = 2) 200, s = 13. Strength data for hikers, presented as peak moments (normalized to body weight) obtained during eccentric, isometric, and concentric contraction (Nm . kg(-1)) respectively were as follows: males - quadriceps: 3.66 (s = 0.68), 3.97 (s = 0.66), 1.82 (s = 0.34); hamstrings: 1.93 (s = 0.22), 1.38 (s = 0.41), 1.05 (s = 0.21); females - quadriceps: 3.84 (s = 0.71), 3.81 (s = 0.58), 1.60 (s = 0.28); hamstrings: 1.75 (s = 0.23), 1.10 (s = 0.16), 0.84 (s = 0.13). The peak moment based H/Q ratios for slow eccentric and concentric contractions were 0.42 (s = 0.11) and 0.39 (s = 0.04) for males and 0.43 (s = 0.06) and 0.39 (s = 0.04) for females respectively. Elite Olympic class sailors demonstrated high VO(2peak) values comparable to those observed in other non-endurance sports. The strength data revealed very high quadriceps strength for hikers, which is likely a result of the high muscle forces encountered during sailing, and a low H/Q ratio. To ensure optimal knee joint stabilization during sailing and other training activities, it is suggested that hikers should counter this strength imbalance by performing additional strength training for the hamstrings muscle group.     

黑龙江省不同项目运动员营养意识与需求调查分析

为了解黑龙江省运动员的营养需求,以提供平衡膳食、科学营养的正确指导,促进其营养意识的提升,对黑龙江省冬夏季不同项目运动员进行日常饮食习惯问卷调查,发现多数运动员早餐营养摄入不足;夜宵摄入大量垃圾食品;大量饮用瓶装饮料代替喝水等一系列问题。建议运动员应多吃主食、多吃蔬果、多吃豆奶制品、少吃油炸食品、减少油脂及盐分摄入,并通过运动营养知识教育培训、健全膳食营养管理体系、配备专兼职营养师等一系列举措调整餐厅膳食配餐及营养结构,以提高运动员营养意识,保证日常饮食健康合理,为运动训练提供营养支持,为运动成绩提高夯实营养基础。     

Survey results of the training, nutrition, and mental preparation of triathletes: practical implications of findings

Although triathlon is growing in popularity at a remarkable rate, it has not been extensively studied. The aims of this research were to identify preparation strategies used by triathletes and to categorize these strategies according to gender and consultation with triathlon coaches. Survey data collected from 401 triathletes (207 males, 194 females) revealed training, nutritional, and mental preparation habits. Most participants engaged in strength training, consumed food and/or fluids during and after training, set training and competition goals, and applied mental preparation strategies during training and the hour before racing. Water was the most commonly consumed fluid; positive self-talk was the most used mental strategy. Participants were more likely to consult with a triathlon coach than a nutrition or sport psychology professional. Athletes with more years of experience in triathlon and those competing in longer distances were more likely to consult a triathlon coach. Female triathletes were more likely than male triathletes to train with others, use mental preparation strategies, and report feeling anxious before competitions. More male triathletes reported using nutritional supplements during training than their female counterparts. These findings add to the limited research base on triathletes' training habits, and hopefully will help guide practitioners who work with this group. The results provide guidance for collaborative efforts among training, nutrition, and mental health professionals to best support triathletes.     

帆船运动员运动性疲劳消除过程营养补充的研究

运用文献资料、营养监控研究方法，针对山东、解放军两队帆船运动员存在的营养不平衡现状，就帆船运动员的合理营养，消除运动性疲劳，促进身体机能快速恢复的营养补充方法进行了分析研究。目的在于使运动员达到营养平衡．加速其运动能力的提高。     

Nutrition for throwers, jumpers, and combined events athletes

Throwers, jumpers, and combined events athletes require speed, strength, power, and a wide variety of technical skills to be successful in their events. Only a handful of studies have assessed the nutritional needs of such athletes. Because of this, recommendations for nutritional requirements to support and enhance training and competition performances for these athletes are made using research findings from sports and exercise protocols similar to their training and competitive events. The goals of the preparation cycle of nutrition periodization for these athletes include attaining desirable body weight, a high ratio of lean body mass to body height, and improving muscular power. Nutritional recommendations for training and competition periods include: (1) meeting energy needs; (2) timing consumption of adequate fluid and electrolyte intakes before, during, and after exercise to promote adequate hydration; (3) timing consumption of carbohydrate intake to provide adequate fuel for energy demands and to spare protein for muscle repair, growth, and maintenance; (4) timing consumption of adequate protein intake to meet protein synthesis and turnover needs; and (5) consuming effective nutritional and dietary supplements. Translating these nutrient and dietary recommendations into guidelines these athletes can apply during training and competition is important for enhancing performance.     

Intensity and physiological strain of competitive ultra-endurance exercise in humans

The aim of this study was to determine the magnitude and pattern of intensity, and physiological strain, of competitive exercise performed across several days, as in adventure racing. Data were obtained from three teams of four athletes (7 males, 5 females; mean age 36 years, s = 11; cycling .VO(2 peak) 53.9 ml . kg(-1) . min(-1), s = 6.3) in an international race (2003 Southern Traverse; 96 - 116 h). Heart rates (HR) averaged 64% (95% confidence interval: +/- 4%) of heart rate range [%HRR = (HR - HR(min))/(HR(max) - HR(min)) x 100] during the first 12 h of racing, fell to 41% (+/-4%) by 24 h, and remained so thereafter. The level and pattern of heart rate were similar across teams, despite one leading and one trailing all other teams. Core temperature remained between 36.0 and 39.2 degrees C despite widely varying thermal stress. Venous samples, obtained before, during, and after the race, revealed increased neutrophil, monocyte and lymphocyte concentrations (P < 0.01), and increased plasma volume (25 +/- 10%; P < 0.01) with a stable sodium concentration. Standardized exercise tests, performed pre and post race, showed little change in the heart rate-work rate relationship (P = 0.53), but a higher perception of effort post race (P < 0.01). These results provide the first comprehensive report of physiological strain associated with adventure racing.     

Body composition and hydration status changes in male and female open-water swimmers during an ultra-endurance event

Body mass changes during ultra-endurance performances have been described for running, cycling and for swimming in a heated pool. The present field study of 20 male and 11 female open-water swimmers investigated the changes in body composition and hydration status during an ultra-endurance event. Body mass, both estimated fat mass and skeletal muscle mass, haematocrit, plasma sodium concentration ([Na+]) and urine specific gravity were determined. Energy intake, energy expenditure and fluid intake were estimated. Males experienced significant reductions in body mass (-0.5 %) and skeletal muscle mass (-1.1 %) (P < 0.05) during the race compared to females who showed no significant changes with regard to these variables (P > 0.05). Changes in percent body fat, fat mass, and fat-free mass were heterogeneous and did not reach statistical significance (P > 0.05) between gender groups. Fluid intake relative to plasma volume was higher in females than in males during the ultra-endurance event. Compared to males, females' average increase in haematocrit was 3.3 percentage points (pp) higher, urine specific gravity decrease 0.1 pp smaller, and plasma [Na+] 1.3 pp higher. The observed patterns of fluid intake, changes in plasma volume, urine specific gravity, and plasma [Na+] suggest that, particularly in females, a combination of fluid shift from blood vessels to interstitial tissue, facilitated by skeletal muscle damage, as well as exercise-associated hyponatremia had occurred. To summarise, changes in body composition and hydration status are different in male compared to female open-water ultra-endurance swimmers.     

Nutritional, lifestyle, and weight control practices of professional jockeys

In this study, we describe diet and lifestyle practices of professional jockeys. Participants completed a 59-item nutrition, lifestyle, and health questionnaire (n = 21) and a 7-day estimated food diary (n = 18). Acute weight loss strategies included the use of saunas (86%), exercising to induce sweating (81%), and restricted energy intake (71%). Of the smokers (38%), 56% used smoking to control weight. Most (86%) jockeys reported attaining a 2-kg weight loss for racing (if required) 24-48 h before or on the designated race-day. Mean daily energy intake (1803 ± 564 kcal) was low and appeared to provide an insufficient availability of energy for sustainment of usual daily and metabolic processes. Carbohydrate intake (3.7 ± 1.3 g · kg?1) was below recommendations for athletes. A substantial proportion of jockeys failed to meet the estimated average requirement and lower threshold intake for a number of micronutrients. Jockeys consumed well below (0-2) the recommended five daily servings of fruit and vegetables set by the World Health Organization. Pressures of the jockey lifestyle and rigid weight limits appear to encourage unhealthy weight management practices in this group and may risk long term-health.     

Energy and macronutrient intake in adolescent sprint athletes: a follow-up study

Macronutrient intake, height, weight, and body composition of 60 adolescent sprint athletes were estimated every 6 months over 3 years. Seven-day food records were analysed based on the Belgian and Dutch food databanks. The age of participants at the start of the 3-year study was 14.8 ± 1.6 years for female athletes and 14.7 ± 1.9 years for male athletes. Girls and boys gained height (3.4 ± 4.6 cm and 5.9 ± 6.6 cm respectively) and weight (5.6 ± 3.5 kg and 8.7 ± 5.5 kg respectively), whereas percent body fat remained unchanged in both girls and boys (around 17.0% and 8.5% respectively). Mean protein intake of around 1.5 g · kg?1 body weight was within recommendations on each occasion for both sexes. Carbohydrate intakes between 5 and 7 g · kg?1 body weight support a training programme of moderate intensity. Total and saturated fat intakes were high at the start of the study (girls: 31.8 ± 3.5% and 12.2 ± 2.0% of energy intake; boys: 30.3 ± 4.6% and 12.0 ± 1.9% of energy intake) and it appeared to be difficult to achieve and maintain lower intakes. Consistent low fluid intakes around 40 ml · kg?1 body weight were observed. General non-stringent advice for improvement of the diet resulted in significant favourable changes only for the consumption of wholegrain bread, vegetables, and soft drinks. Dietary habits of adolescent sprint athletes are not always according to guidelines and are relatively stable but repeated advice can induce moderate improvements.     

不同项目运动员身体成分与机能的关系

以上海市二线运动员为研究对象,探讨不同项目运动员身体成分与运动机能的关系,以期为今后运动员选材和运动训练提供科学依据.对上海市短跑、自行车、击剑3项目的117名二线运动员(男60名,女57名)进行身体成分、无氧能力和有氧能力测试.结果发现:3项目男女运动员体重、肌肉、蛋白质与无氧能力指标基本都存在中度或高度的相关关系,男女运动员肌肉、蛋白质总量,体重与血乳酸都呈低度相关关系;肌肉、蛋白质、体重与绝对摄氧量都有高度的相关关系,而与相对摄氧量都只存在低度或负相关关系;3项目体脂与无氧能力有关指标和有氧能力相关低且呈负相关趋势.说明各种身体成分与身体机能有密切关系,但由于不同项目特点不一样,因此其相关关系也有明显的差别.     

青少年运动员的膳食营养偏差研究

研究目的：探讨青少年运动员对营养知识的掌握、饮食习惯的现状和膳食营养状况,为指导运动员合理膳食营养及开展营养知识宣传教育提供依据。研究方法：以浦东新区青少年运动员为对象,共302人。采用膳食调查和营养知识和饮食习惯的问卷调查。研究结果：男、女青少年运动员的能量摄入量均不足,且三大能源物质比例摄取不合理;结论与建议：1加强供能物质谷类食物的摄入2加强钙的摄入3多吃蔬菜和水果,补充维生素。     

湖北省重竞技运动员营养知识-态度-行为（KAP）调查

目的了解湖北省重竞技项目运动员的营养知识知晓、饮食态度和饮食行为的现状,以便采取相应的措施达到合理营养。方法据营养＂知-信-行＂行为模式,设计营养KAP问卷,对冬训期间湖北省重竞技项目全体在训运动员进行调查。结果重竞技项目运动员营养知识平均得分4.23±1.92,营养知识处于普遍缺乏状态;81.6%运动员按自己的口味习惯选择食物,仅有17.1%考虑到营养搭配,2.3%考虑到营养合理;部分运动员不吃早餐,水果、牛奶摄入频次少,饮食行为不规范;但有着较好的接受营养知识教育的态度。结论采取各种有效措施对运动员加强营养知识教育,使运动员的膳食行为健康合理。