Energy and carbohydrate for training and recovery

Soccer players should achieve an energy intake that provides sufficient carbohydrate to fuel the training and competition programme, supplies all nutrient requirements, and allows manipulation of energy or nutrient balance to achieve changes in lean body mass, body fat or growth. Although the traditional culture of soccer has focused on carbohydrate intake for immediate match preparation, top players should adapt their carbohydrate intake on a daily basis to ensure adequate fuel for training and recovery between matches. For players with a mobile playing style, there is sound evidence that dietary programmes that restore and even super-compensate muscle glycogen levels can enhance activity patterns during matches. This will presumably also benefit intensive training, such as twice daily practices. As well as achieving a total intake of carbohydrate commensurate with fuel needs, the everyday diet should promote strategic intake of carbohydrate and protein before and after key training sessions to optimize the adaptations and enhance recovery. The achievement of the ideal physique for soccer is a long-term goal that should be undertaken over successive years, and particularly during the off-season and pre-season. An increase in lean body mass or a decrease in body fat is the product of a targeted training and eating programme. Consultation with a sports nutrition expert can assist soccer players to manipulate energy and nutrient intake to meet such goals. Players should be warned against the accidental or deliberate mismatch of energy intake and energy expenditure, such that energy availability (intake minus the cost of exercise) falls below 125 kJ (30 kcal) per kilogram of fat-free mass per day. Such low energy availability causes disturbances to hormonal, metabolic, and immune function.     

Time-restricted feeding in young men performing resistance training: A randomized controlled trial†

A randomized controlled trial was conducted to examine eight weeks of resistance training (RT) with and without time-restricted feeding (TRF) in order to assess nutrient intake and changes in body composition and muscular strength in young recreationally active males. The TRF programme consisted of consuming all calories within a four-hour period of time for four days per week, but included no limitations on quantities or types of foods consumed. The RT programme was performed three days per week and consisted of alternating upper and lower body workouts. For each exercise, four sets leading to muscular failure between 8 and 12 repetitions were employed. Research visits were conducted at baseline, four, and eight weeks after study commencement. Measurements of total body composition by dual-energy X-ray absorptiometry and muscle cross-sectional area by ultrasound were obtained. Upper and lower body strength and endurance were assessed, and four-day dietary records were collected. TRF reduced energy intake by ～650?kcal per day of TRF, but did not affect total body composition within the duration of the study. Cross-sectional area of the biceps brachii and rectus femoris increased in both groups. Effect size data indicate a gain in lean soft tissue in the group that performed RT without TRF (+2.3?kg, d?=?0.25). Upper and lower body strength and lower body muscular endurance increased in both groups, but effect sizes demonstrate greater improvements in the TRF group. Overall, TRF reduced energy intake and did not adversely affect lean mass retention or muscular improvements with short-term RT in young males.     

Effect of combined carbohydrate-protein ingestion on markers of recovery after simulated rugby union match-play

In this study, we investigated the effect of ingesting carbohydrate alone or carbohydrate with protein on functional and metabolic markers of recovery from a rugby union-specific shuttle running protocol. On three occasions, at least one week apart in a counterbalanced order, nine experienced male rugby union forwards ingested placebo, carbohydrate (1.2 g · kg body mass(-1) · h(-1)) or carbohydrate with protein (0.4 g · kg body mass(-1) · h(-1)) before, during, and after a rugby union-specific protocol. Markers of muscle damage (creatine kinase: before, 258 ± 171 U · L(-1) vs. 24 h after, 574 ± 285 U · L(-1); myoglobin: pre, 50 ± 18 vs. immediately after, 210 ± 84 nmol · L(-1); P < 0.05) and muscle soreness (1, 2, and 3 [maximum soreness = 8] for before, immediately after, and 24 h after exercise, respectively) increased. Leg strength and repeated 6-s cycle sprint mean power were slightly reduced after exercise (93% and 95% of pre-exercise values, respectively; P < 0.05), but were almost fully recovered after 24 h (97% and 99% of pre-exercise values, respectively). There were no differences between trials for any measure. These results indicate that in experienced rugby players, the small degree of muscle damage and reduction in function induced by the exercise protocol were not attenuated by the ingestion of carbohydrate and protein.     

抗阻力训练对排球运动员腰背肌肉筋膜炎的康复研究

目的：探讨排球运动员腰背肌肉筋膜炎的发生因素与运动疗法的康复作用。方法：30例排球运动员腰背肌肉筋膜炎患者随机分为实验组15例、对照组15例。实验组患者采用抗阻力运动康复方案、对照组采用传统推拿,在30天时统计康复结果。结果：实验组在腰背疼痛视觉模糊量尺测定、腰背功能评价两项成绩均显著优于对照组。结论：抗阻力康复方案对排球运动员的腰背肌肉筋膜炎具有良好疗效。     

有氧健身锻炼对改善老年人体成分的作用

采用皮褶法对湖北省荆州市长期坚持有氧锻炼和不锻炼的老年人体成分分别进行了测试 ,结果显示 ,长期的有氧锻炼能使老年人的去脂体重增加 ,腹部脂肪减少。说明长期的有氧锻炼能减缓老年人肌肉的萎缩以及肝脏等内脏组织的丢失 ,并对防止肥胖也有一定的作用。     

Relationship between leg stiffness and lower body injuries in professional Australian football

Leg stiffness is a modifiable mechanical property that may be related to soft tissue injury risk. The purpose of this study was to examine mean leg stiffness and bilateral differences in leg stiffness across an entire professional Australian Football League (AFL) season, and determine whether this parameter was related to the incidence of lower body soft tissue injury. The stiffness of the left and right legs of 39 professional AFL players (age 24.4 ± 4.4 years, body mass 87.4 ± 8.1 kg, stature 1.87 ± 0.07 m) was measured using a unilateral hopping test at least once per month throughout the season. Injury data were obtained directly from the head medical officer at the football club. Mean leg stiffness and bilateral differences in leg stiffness were compared between the injured and non-injured players. There was no difference between the season mean leg stiffness values for the injured (219.3 ± 16.1 N x m(-1) x kg(-1)) and non-injured (217.4 ± 14.9 N x m(-1) x kg(-1); P = 0.721) groups. The injured group (7.5 ± 3.0%) recorded a significantly higher season mean bilateral difference in leg stiffness than the non-injured group (5.5 ± 1.3%; P = 0.05). A relatively high bilateral difference in leg stiffness appears to be related to the incidence of soft tissue injury in Australian football players. This information is of particular importance to medical and conditioning staff across a variety of sports.     

Athlete burnout in elite sport: A self-determination perspective

Abstract

The practice of exercise has shown to be beneficial to quality of life of individuals with HIV/AIDS. Thus, the present study analysed the effects of a combined exercise training in persons living with HIV/AIDS. Ten participants participated in the present study. The following variables were analysed: viral load and cell counts for TCD4+/TCD8; maximal oxygen consumption (VO_2max); total mass, absolute fat mass, relative fat mass, absolute lean mass, relative lean mass and body mass index; fasting glycaemia, fasting insulinaemia, homeostatic model assessment (HOMA) index (insulin resistance – homeostatic model assessment (IR-HOMA)); total cholesterol, triglycerides, high-density lipoprotein (HDL), very low-density lipoprotein (VLDL), low-density lipoprotein (LDL); superoxide dismutase, catalase, glutathione peroxidase activities; thiobarbituric acid reactive substances. The combined exercise training consisted of resistance exercises plus aerobic training (60 min · session^?1, three times per week, during 20 weeks). The number of TCD4+ cells, absolute lean mass and relative lean mass, muscle strength for the 45° leg press, seated row and triceps extension, HDL-c levels as well as VO_2max increased post-training. The activity of superoxide dismutase, catalase, glutathione peroxidase enzymes and thiobarbituric acid reactive substances levels were diminished post-training. Finally, it can be concluded that combined exercise training is able to change positively several variables related to health of individuals with HIV/AIDS, mainly the immune system as well as antioxidant mechanisms re-establishment.     

综合干预对肥胖男性青少年身体形态和血液生化指标的影响

目的:对7名肥胖男性青少年进行为期21天的封闭式综合干预(运动、营养、生活方式、心理教育等)减肥。通过比较综合干预前后研究对象身体形态指标、血液生化指标和生活习惯的变化,探讨综合干预对肥胖青少年健康的改善和促进作用。方法:以2011年参加沈阳体育学院运动智能控重中心减肥夏令营的7名体脂率>29%的男性肥胖青少年为研究对象,综合干预开始时测试身高、体重、体脂百分比(PBF)、身体质量指数(BMI)、脂肪体重、瘦体重、腰围、臀围等身体形态指标和血脂四项、血清葡萄糖(Glu)和血清胰岛素(FIN)等血液生化指标。经运动负荷试验和体格检查,排除心血管机能障碍等危险因素后确定个体减肥方案。采取运动干预、营养干预、心理干预以及生活方式干预等综合干预方案,21天后测定相同指标并与刚入营时进行比较。结果:经过21天的综合干预,肥胖青少年体重、身体质量指数(BMI)、体脂百分比(PBF)、脂肪体重、腰围、臀围等身体形态指标和空腹血脂、血清胰岛素(FIN)指标明显改善,空腹血糖(Glu)没有变化。结论:21天的综合干预对肥胖男性青少年身体形态和血液生化指标有明显改善作用。     

Body composition assessment of English Premier League soccer players: a comparative DXA analysis of first team,U21 and U18 squads

Professional soccer players from the first team (1st team, n = 27), under twenty-one (U21, n = 21) and under eighteen (U18, n = 35) squads of an English Premier League soccer team were assessed for whole body and regional estimates of body composition using dual-energy X-ray absorptiometry (DXA). Per cent body fat was lower in 1st team (10.0 ± 1.6) compared with both U21 (11.6 ± 2.5, P = 0.02) and U18 (11.4 ± 2.6, P = 0.01) players. However, this difference was not due to variations (P = 0.23) in fat mass between squads (7.8 ± 1.6 v 8.8 ± 2.1 v 8.2 ± 2.4 kg, respectively) but rather the presence of more lean mass in 1st team (66.9 ± 7.1 kg, P < 0.01) and U21 (64.6 ± 6.5 kg, P = 0.02) compared with U18 (60.6 ± 6.3 kg) players. Accordingly, fat mass index was not different (P = 0.138) between squads, whereas lean mass index was greater (P < 0.01) in 1st team players (20.0 ± 1.1 kg · m^?2) compared with U18 players (18.8 ± 1.4 kg · m^?2). Differences in lean mass were also reflective of higher lean tissue mass in all regions, for example, upper limbs/lower limbs and trunk. Data suggest that training and nutritional interventions for younger players should therefore be targeted to lean mass growth as opposed to body fat loss.     

Adverse effects of energy restriction on myogenic enzymes in judoists

In this study, we examined the effects of weight reduction by restricting energy intake on muscle function and serum concentrations of myogenic enzymes in judoists. Twenty-seven male judoists aged 19.3 +/- 0.6 years (mean +/- s) were divided into three groups based on the extent of body weight reduction: high weight reduction (height 1.70 +/- 0.05 m, body mass 78.5 +/- 13.6 kg), low weight reduction (height 1.70 +/- 0.05 m, body mass 80.7 +/- 13.1 kg) and a group that maintained body weight while continuing to perform exercise training (height 1.78 +/- 0.07 m, body mass 78.7 +/- 8.8 kg). Body composition, blood biochemistry, energy intake and anaerobic power were assessed on four occasions: 20 days (baseline data), 4 days and 1 day before and 7 days after competition. Compared with baseline, body mass and fat-free mass were significantly lower 1 day before competition in the high and low weight reduction groups (both P < 0.01); these changes persisted for 7 days after competition in the high weight reduction group. Serum creatine kinase was significantly elevated 1 day before competition in all groups (all P < 0.05), and remained higher 7 days after competition in both the high and low weight reduction groups. Compared with baseline, maximal anaerobic power was significantly lower 1 day before competition only in the high weight reduction group (P < 0.01). Our results suggest that energy restriction in addition to intense exercise training before major competition has an adverse effect on anaerobic power and elevates serum creatine kinase concentration, leading to an impairment of muscular function and an increased susceptibility of muscle tissue to injury.     

Specific muscular development in under-18 soccer players

A comparison of the under-18 (U-18) and under-16 (U-16) squads of the Canadian national soccer team with a representative sample of Canadians (Canada Fitness Survey, 1983) showed a tendency for the development or selection of the older players in teams of stature (U-18, 175.8 cm; U-16, 171.1 cm; CFS, 170.9 cm) and lean body mass (U-18, 63.4; U-16, 57.9; CFS, 54.2 kg). The larger lean mass of the older players could not be explained simply by size. The U-18s also showed greater isokinetic leg extension force (particularly for rapid movements) and explosive strength (vertical jump) relative to the younger players, although the knee extension force was less than in some classes of athlete. Part of the gain in mass seems due to local training of the hip and leg muscles and part to a more general muscular development. Contrary to some reports, the hip flexibility of the Canadian players (sit and reach test) was greater than for a national sample; this may be important in avoiding soft tissue injuries to the legs. However, aerobic power (58.3 +/- 5.3 ml kg-1 min-1) and body fat (8.0 +/- 1.1%) were unremarkable.     

健美操运动员前交叉韧带损伤的康复方案研究——Ⅰ度损伤的保守治疗

膝关节是人体负重和运动的主要关节,前交叉韧带(ACL)损伤是膝关节最常见运动损伤之一,而健美操运动也是造成膝关节前交叉韧带损伤的项目之一,本文通过运用文献综述的方法,广泛收集有关膝关节ACL损伤的基本理论及防治知识,通过前交叉韧带的生理解剖结构,并结合健美操项目的运动特点来分析造成前交叉韧带一度损伤的原因及根据原因提出预防措施,针对前交叉韧带一度损伤的早、中、晚三期的病理演变特征提出康复方案,对以后前交叉韧带一度损伤保守治疗的快速康复提供理论基础,并对以后健美操训练中前交叉韧带损伤的预防和韧带重建术后康复训练有重要意义。     

The scientific foundations and associated injury risks of early soccer specialisation

ABSTRACT

Early specialisation is characterised by formal participation in a single sport at the exclusion of others. Limited data are available to support this approach in the development of soccer players who attain elite status later in life. Of growing concern is the associated increased risk of injury and suggestions that single sport specialisation is a risk factor independent of age, growth, biological maturation and training volumes. In the United Kingdom, elite soccer organisations have recently adopted an early sport specialisation approach following the introduction of the Elite Player Performance Plan. A key tenet of this programme is increased opportunities for training through a marked rise in the specified on-pitch hours per week. The accumulation of high training hours may be less of a relevant marker for success, and the impact of such a significant increase in training volume for young athletes who are experiencing a range of growth and maturational processes is currently unknown. This critical commentary includes an evidence-based discussion of the effectiveness of early sport specialisation and the potential injury risks associated with such programmes placing a specific focus on elite male youth soccer players. Available data indicate that modifications to the existing Elite Player Performance Plan framework could enhance players’ development and reduce injury risk. Proposed alterations include reduced volume of soccer-specific training at key stages of growth and maturation and guidelines for the provision of a greater variety of physical activities that are integrated within other programme components.     

优秀柔道运动员腰肌劳损的康复性体能训练研究

康复性体能训练是体能训练领域较新的研究和实践方向,同时发展也较为迅速,它为运动员的损伤预防和伤病恢复提供了很好的解决方向和方法。程＊＊,中国柔道队队员,2012年10月,腰部出现不适,大强度训练后出现疼痛,后经诊断为腰肌劳损。基于此,研究运用等速肌力测试、体成份测试和功能检查等方法对程＊＊的身体功能情况进行系统的阶段性的评估,并根据腰部损伤情况制定针对性的康复体能训练计划。经过3个阶段25周的康复性体能训练后,程＊＊腰肌劳损的伤病得到了很好的恢复,并且体能水平得到了较大程度的提高,这为其在12届全国运动会上取得冠军的比赛成绩打下了坚实的基础。     

运动与共轭亚油酸对青春期肥胖大鼠内脏脂肪及肝肾功能的影响

目的：探讨运动与CLA对青春期肥胖大鼠内脏脂肪及肝肾功能的影响。方法：高脂饲养大鼠建模7周后,取24只肥胖大鼠随机分成4组,每组6只,分别为对照组、CLA组、运动组、运动＋CLA组。运动方案为跑台坡度0°,速度为21-25 m/min,总运动时间60min/天,5次/周,给药方案为运动后即刻灌喂1.6g/kg剂量的CLA,共持续干预8周。干预结束后麻醉大鼠采集血液及组织,测肝肾功能和内脏脂肪重量。结果：8周干预后,运动组、运动＋CLA组的体重、内脏脂肪重量及体脂率均明显低于对照组、CLA 组（P＜0.01,P＜0.05）,对照组和CLA组无明显差异（P〉0.05）;对照组、运动组、运动＋CLA组谷草转氨酶和谷草丙比数值明显高于CLA组（P＜0.01）,其他组别之间无明显差异（P＞0.05）;运动组、运动＋CLA组血尿素氮和肌酐较对照组、CLA 组有变化,但无明显差异（P＞0.05）。结论：8周运动与 CLA干预可有效降低青春期肥胖大鼠体重、内脏脂肪重量、体脂率,运动结合CLA能显著减少内脏脂肪含量,增加瘦体重,降低体脂率,具有明显的减肥效果。运动和CLA干预有一定的保肝作用,对肾脏功能无明显影响。     

Protection against muscle damage in competitive sports players: the effect of the immunomodulator AM3

Strenuous physical exercise of the limb muscles commonly results in damage, especially when that exercise is intense, prolonged and includes eccentric contractions. Many factors contribute to exercise-induced muscle injury and the mechanism is likely to differ with the type of exercise. Competitive sports players are highly susceptible to this type of injury. AM3 is an orally administered immunomodulator that reduces the synthesis of proinflammatory cytokines and normalizes defective cellular immune fractions. The ability of AM3 to prevent chronic muscle injury following strenuous exercise characterized by eccentric muscle contraction was evaluated in a double-blind and randomized pilot study. Fourteen professional male volleyball players from the First Division of the Spanish Volleyball League volunteered to take part. The participants were randomized to receive either placebo (n=7) or AM3 (n=7). The physical characteristics (mean+/-s) of the placebo group were as follows: age 25.7+/-2.1 years, body mass 87.2+/-4.1 kg, height 1.89+/-0.07 m, maximal oxygen uptake 65.3+/-4.2 ml.kg(-1).min(-1). Those of the AM3 group were as follows: age 26.1+/-1.9 years, body mass 85.8+/-6.1 kg, height 1.91+/-0.07 m, maximal oxygen uptake 64.6+/-4.5 ml.kg(-1).min(-1). All participants were evaluated for biochemical indices of muscle damage, including concentrations of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, creatine kinase (CK) and its MB fraction (CK-MB), myoglobin, lactate dehydrogenase, urea, creatinine and gamma-glutamyltranspeptidase, both before and 30 days after treatment (over the peak of the competitive season). In the placebo group, competitive exercise (i.e. volleyball) was accompanied by significant increases in creatine kinase (494+/-51 to 560+/-53 IU.l(-1), P < 0.05) and myoglobin (76.8+/-2.9 to 83.9+/-3.1 microg.l(-1), P < 0.05); aspartate aminotransferase (30.8+/-3.0 to 31.1+/-2.9 IU.l(-1)) and lactate dehydrogenase (380+/-31 to 376+/-29 IU.l(-1)) were relatively unchanged after the 30 days maximum effort. AM3 not only inhibited these changes, it led to a decrease from baseline serum concentrations of creatine kinase (503+/-49 to 316+/-37 IU.l(-1), P < 0.05) and myoglobin (80.1+/-3.2 to 44.1+/-2.6 IU.l(-1), P < 0.05), as well as aspartate aminotransferase (31.1+/-3.3 to 26.1+/-2.7 IU.l(-1), P < 0.05) and lactate dehydrogenase (368+/-34 to 310+/-3 IU.l(-1), P < 0.05). The concentration of CK-MB was also significantly decreased from baseline with AM3 treatment (11.6+/-1.2 to 5.0+/-0.7 IU.l(-1), P < 0.05), but not with placebo (11.4+/-1.1 to 10.8+/-1.4 IU.l(-1)). In conclusion, the use of immunomodulators, such as AM3, by elite sportspersons during competition significantly reduces serum concentrations of proteins associated with muscle damage.     

Adverse effects of energy restriction on myogenic enzymes in judoists

In this study, we examined the effects of weight reduction by restricting energy intake on muscle function and serum concentrations of myogenic enzymes in judoists. Twenty-seven male judoists aged 19.3±0.6 years (mean±s) were divided into three groups based on the extent of body weight reduction: high weight reduction (height 1.70±0.05?m, body mass 78.5 ±13.6?kg), low weight reduction (height 1.70±0.05?m, body mass 80.7±13.1?kg) and a group that maintained body weight while continuing to perform exercise training (height 1.78± 0.07?m, body mass 78.7±8.8?kg). Body composition, blood biochemistry, energy intake and anaerobic power were assessed on four occasions: 20 days (baseline data), 4 days and 1 day before and 7 days after competition. Compared with baseline, body mass and fat-free mass were significantly lower 1 day before competition in the high and low weight reduction groups (both P?<0.01); these changes persisted for 7 days after competition in the high weight reduction group. Serum creatine kinase was significantly elevated 1 day before competition in all groups (all P?<0.05), and remained higher 7 days after competition in both the high and low weight reduction groups. Compared with baseline, maximal anaerobic power was significantly lower 1 day before competition only in the high weight reduction group (P?<0.01). Our results suggest that energy restriction in addition to intense exercise training before major competition has an adverse effect on anaerobic power and elevates serum creatine kinase concentration, leading to an impairment of muscular function and an increased susceptibility of muscle tissue to injury.     

Associated ACL risk factors differences during an unanticipated volleyball blocking movement

ABSTRACT

The lateral tilt of the arms accompanied by trunk lateral tilt is a typical blocking manoeuvre in volleyball. However, during this unanticipated blocking movement, an associated risk of ACL injury may result. The aim of the present study was to compare associative ACL risk factors at the initial contact and the first and second peak of VGRF during an unanticipated blocking movement with different arm positions. Synchronized kinematic and kinetic data were collected for each trial of each condition. Student paired t-tests and effect size were used to determine differences between two conditions (S – with arms straight up from the body) and (T – with the arms and trunk laterally tilted). The results showed that the T condition significantly decreases knee flexion, increases VGRF at the foot contact, first peak force and increases the valgus moment at the first peak force. The values of the associated risk factors for a non-contact ACL injury appear to be related to the tilted arm position accompanied by trunk tilt towards to right lower limb during landing. The players should be taught to land with greater knee flexion and, if possible, a double-leg landing to decrease right lower limb loading during the blocking manoeuvre.     

Specific muscular development in under‐18 soccer players

A comparison of the under‐18 (U‐18) and under‐16 (U‐16) squads of the Canadian national soccer team with a representative sample of Canadians (Canada Fitness Survey, 1983) showed a tendency for the development or selection of the older players in teams of stature (U‐18, 175.8 cm; U‐16, 171.1 cm; CFS, 170.9 cm) and lean body mass (U‐18, 63.4; U‐16, 57.9; CFS, 54.2 kg). The larger lean mass of the older players could not be explained simply by size. The U‐18s also showed greater isokinetic leg extension force (particularly for rapid movements) and explosive strength (vertical jump) relative to the younger players, although the knee extension force was less than in some classes of athlete. Part of the gain in mass seems due to local training of the hip and leg muscles and part to a more general muscular development. Contrary to some reports, the hip flexibility of the Canadian players (sit and reach test) was greater than for a national sample; this may be important in avoiding soft tissue injuries to the legs. However, aerobic power (58.3±5.3 ml kg^‐1 min^‐1) and body fat (8.0±l.l%) were unremarkable.