Blood Lipids and Lipoproteins in Soccer Players

本研究の目的は､関連した文献から1)ｻｯｶｰ選手の血清脂質およびﾘﾎﾟﾀﾝﾊﾟｸ質に関する横断的研究を食事や栄養素等摂取量､肥満､喫煙､ｱﾙｺｰﾙ摂取量､月経周期､競技ﾎﾟｼﾞｼｮﾝなどの潜在的な交絡因子を含めて検討し､2)90分間のｻｯｶｰ競技の血清脂質およびﾘﾎﾟﾀﾝﾊﾟｸ質に対する急性効果､3)競技者やﾚｸﾘｴｰｼｮﾝとして行っている者の定期的なｻｯｶｰﾄﾚｰﾆﾝｸﾞが血清脂質およびﾘﾎﾟﾀﾝﾊﾟｸ質に対する効果につい検討することである｡ｻｯｶｰ選手の血中脂質における最も一致した見解は､高比重ﾘﾎﾟﾀﾝﾊﾟｸｺﾚｽﾃﾛｰﾙ(HDL-C)が対照群よりも高値を示すことである｡血中脂質およびﾘﾎﾟﾀﾝﾊﾟｸ質における90分間のｻｯｶｰの試合の急性効果に関する研究では､特に血漿量の変化を補正する必要がある｡定期的なｻｯｶｰﾄﾚｰﾆﾝｸﾞを行えば､異なる年齢層において総ｺﾚｽﾃﾛｰﾙ､ﾄﾘｸﾞﾘｾﾘﾄﾞ､低比重ﾘﾎﾟﾀﾝﾊﾟｸｺﾚｽﾃﾛｰﾙ(LDL-C)を減少させ､HDL-C を増加させることができる｡訓練していない男女のﾚｸﾘｴｰｼｮﾝとしてのｻｯｶｰﾄﾚｰﾆﾝｸﾞにおける血中脂質への効果に関する最も一致した見解は､LDL-C および/または LDL-C/ HDL-C 比が低下することである｡ｻｯｶｰ選手における血中脂質およびﾘﾎﾟﾀﾝﾊﾟｸ質の変化は､ﾘﾎﾟﾀﾝﾊﾟｸ質ﾘﾊﾟｰｾﾞ､ﾚｼﾁﾝ:ｺﾚｽﾃﾛｰﾙｱｼﾙﾄﾗﾝｽﾌｪﾗｰｾﾞおよび肝性ﾘﾊﾟｰｾﾞの活性ﾚﾍﾞﾙの変化によるものである可能性が考えられる｡ｻｯｶｰ選手における今後の研究は､血中脂質およびﾘﾎﾟﾀﾝﾊﾟｸ質が変化するﾒｶﾆｽﾞﾑに向けられる必要がある｡これらの研究では特に知見が不足している女性や青年､若年成人に焦点を当てるべきである｡The purpose of this study was to review the related literature to examine: 1) cross-sectional studies on serum lipids and lipoproteins in soccer players in the context of the potentially confounding factors such as dietary and nutritional intakes, obesity, cigarette smoking, alcohol intake, menstrual cycle, and playing positions in soccer, 2) acute effects of 90-min soccer match, and 3) effects of regular soccer training on lipid parameters in competitive and recreational soccer players. The most consistent observation regarding cross-sectional studies on lipid profile in soccer players is significantly higher high-density-lipoprotein cholesterol (HDL-C) than the controls. Research on the acute effects of 90-min of soccer match on the blood lipids and lipoproteins needs further attention, particularly it should correct plasma volume shifts. Participation in regular soccer training could decrease total cholesterol, triglycerides, low-density-lipoprotein cholesterol (LDL-C) and increase HDL-C in soccer players of different age groups. The most consistent observation regarding effects of recreational soccer training on lipid profile in both untrained men and women is significantly lowered LDL-C and / or LDL-C / HDL-C ratio. The changes in lipids and lipoproteins in soccer players could be caused by changes in activity levels of lipoprotein lipase, lecithin: cholesterol acyltransferase, and hepatic lipase. Future research investigating blood lipids and lipoproteins in soccer players should direct research towards the underlying mechanisms for changes in blood lipids and lipoproteins. These studies should, in particular, focus on women, adolescents and young adults since there is a paucity of information in the literature in this area

Effect of a Carbohydrate-Electrolyte Solution on Fluid Balance and Performance at a Thermoneutral Environment in International-Level Fencers

© 2019 by the National Strength & Conditioning Association.Chryssanthopoulos, C, Tsolakis, C, Bottoms, L, Toubekis, A, Zacharogiannis, E, Pafili, Z, and Maridaki, M. Effect of a carbohydrate-electrolyte solution on fluid balance and performance at a thermoneutral environment in international-level fencers. J Strength Cond Res 34(1): 152-161, 2020-The purpose of the study was to examine a possible effect of a carbohydrate-electrolyte (CHO-E) solution on fluid balance and performance in fencing at a thermoneutral environment. Sixteen fencers performed two 120-minute training sessions separated by 7-14 days under similar environmental conditions (temperature: 20.3° C and humidity: 45-47%). Each session consisted of 60-minute conditioning exercises followed by 10 bouts of 3 minutes against the same opponent with 3-minute interval between each bout. Participants ingested at regular intervals either a 6% CHO-E solution or an artificially sweetened water (PL) in a counterbalanced order. No difference was observed between conditions in the heart rate responses, perceived exertion, changes in plasma volume, urine specific gravity, number of bouts won or lost, or points for and against. Considerable variability was observed in body mass changes that revealed significant differences at the time level (i.e., pre- vs. post-exercise) (F1,15 = 9.31, p = 0.008, η = 0.38), whereas no difference was found between conditions (i.e., CHO-E vs. PL) (F1,15 = 0.43, p = 0.52, η = 0.03) and conditions × time interaction (F1,15 = 3.57, p = 0.078, η = 0.19). Fluid loss was not significantly different between conditions (p = 0.08, d = 0.47). The blood glucose level was higher (p < 0.01) after exercise in CHO-E, whereas the blood lactate level was similar between conditions. In conclusion, the CHO-E solution was as effective as the artificially sweetened water in terms of fluid balance and fencing performance at a thermoneutral environment. Because of large individual variability, fencers should monitor their fluid intake and body fluid loss in training and competition.Peer reviewedFinal Accepted Versio

Cold applications for recovery in adolescent athletes: a systematic review and meta analysis

Recovery and regeneration modalities have been developed empirically over the years to help and support training programmes aimed at maximizing athletic performance. Professional athletes undergo numerous training sessions, characterized by differing modalities of varying volumes and intensities, with the aim of physiological adaptation leading to improved performance. Scientific support to athletes focuses on improving the chances of a training programme producing the largest adaptive response. In competition it is mainly targeted at maximizing the chances of optimal performance and recovery when high performance levels are required repeatedly in quick succession (e.g. heats/finals). In recent years, a lot of emphasis has been put on recovery modalities. In particular, emphasis has been placed on the need to reduce the delayed onset of muscle soreness (DOMS) typically evident following training and competitive activities inducing a certain degree of muscle damage. One of the most used recovery modalities consists of cold-water immersion and/or ice/cold applications to muscles affected by DOMS. While the scientific literature has provided a rationale for such modalities to reduce pain in athletes and recreationally active adults, it is doubtful if this rationale is appropriate to aid training with adolescent athletes. In particular, since these methods have been suggested to potentially impair the muscle remodeling process leading to muscle hypertrophy. While this debate is still active in the literature, many coaches adopt such practices in youth populations, simply transferring what they see in elite sportspeople directly; without questioning the rationale, safety or effectiveness as well as the potential for such activity to reduce the adaptive potential of skeletal muscle remodeling in adolescent athletes. The aim of this review was to assess the current knowledge base on the use of ice/cold applications for recovery purposes in adolescent athletes in order to provide useful guidelines for sports scientists, medical practitioners, physiotherapists and coaches working with such populations as well as developing research questions for further research activities in this area. Based on the current evidence, it seems clear that evidence for acute benefits of such interventions are scarce and more work is needed to ascertain the physiological implications on a pre or peri-pubertal population

Muscle activation patterns in shoulder impingement patients

Introduction: Shoulder impingement is one of the most common presentations of shoulder joint problems 1. It appears to be caused by a reduction in the sub-acromial space as the humerus abducts between 60o -120o – the 'painful arc'. Structures between the humeral head and the acromion are thus pinched causing pain and further pathology 2. Shoulder muscle activity can influence this joint space but it is unclear whether this is a cause or effect in impingement patients. This study aimed to observe muscle activation patterns in normal and impingement shoulder patients and determine if there were any significant differences. Method: 19 adult subjects were asked to perform shoulder abduction in their symptomatic arm and non-symptomatic. 10 of these subjects (age 47.9 ± 11.2) were screened for shoulder impingement, and 9 subjects (age 38.9 ± 14.3) had no history of shoulder pathology. Surface EMG was used to collect data for 6 shoulder muscles (Upper, middle and lower trapezius, serratus anterior, infraspinatus, middle deltoids) which was then filtered and fully rectified. Subjects performed 3 smooth unilateral abduction movements at a cadence of 16 beats of a metronome set at 60bpm, and the mean of their results was recorded. T-tests were used to indicate any statistical significance in the data sets. Significance was set at P<0.05. Results: There was a significant difference in muscle activation with serratus anterior in particular showing a very low level of activation throughout the range when compared to normal shoulder activation patterns (<30%). Middle deltoid recruitment was significantly reduced between 60-90o in the impingement group (30:58%).Trends were noted in other muscles with upper trapezius and infraspinatus activating more rapidly and erratically (63:25%; 60:27% respectively), and lower trapezius with less recruitment (13:30%) in the patient group, although these did not quite reach significance. Conclusion: There appears to be some interesting alterations in muscle recruitment patterns in impingement shoulder patients when compared against their own unaffected shoulders and the control group. In particular changes in scapula control (serratus anterior and trapezius) and lateral rotation (infraspinatus), which have direct influence on the sub-acromial space, should be noted. It is still not clear whether these alterations are causative or reactionary, but this finding gives a clear indication to the importance of addressing muscle reeducation as part of a rehabilitation programme in shoulder impingement patients

Eye quietness and quiet eye in expert and novice golf performance: an electrooculographic analysis

Quiet eye (QE) is the final ocular fixation on the target of an action (e.g., the ball in golf putting). Camerabased eye-tracking studies have consistently found longer QE durations in experts than novices; however, mechanisms underlying QE are not known. To offer a new perspective we examined the feasibility of measuring the QE using electrooculography (EOG) and developed an index to assess ocular activity across time: eye quietness (EQ). Ten expert and ten novice golfers putted 60 balls to a 2.4 m distant hole. Horizontal EOG (2ms resolution) was recorded from two electrodes placed on the outer sides of the eyes. QE duration was measured using a EOG voltage threshold and comprised the sum of the pre-movement and post-movement initiation components. EQ was computed as the standard deviation of the EOG in 0.5 s bins from –4 to +2 s, relative to backswing initiation: lower values indicate less movement of the eyes, hence greater quietness. Finally, we measured club-ball address and swing durations. T-tests showed that total QE did not differ between groups (p = .31); however, experts had marginally shorter pre-movement QE (p = .08) and longer post-movement QE (p < .001) than novices. A group × time ANOVA revealed that experts had less EQ before backswing initiation and greater EQ after backswing initiation (p = .002). QE durations were inversely correlated with EQ from –1.5 to 1 s (rs = –.48 - –.90, ps = .03 - .001). Experts had longer swing durations than novices (p = .01) and, importantly, swing durations correlated positively with post-movement QE (r = .52, p = .02) and negatively with EQ from 0.5 to 1s (r = –.63, p = .003). This study demonstrates the feasibility of measuring ocular activity using EOG and validates EQ as an index of ocular activity. Its findings challenge the dominant perspective on QE and provide new evidence that expert-novice differences in ocular activity may reflect differences in the kinematics of how experts and novices execute skills

National Athletic Trainers\u27 Association Position Statement: Safe Weight Loss and Maintenance Practices in Sport and Exercise

Objective: To present athletic trainers with recommendations for safe weight loss and weight maintenance practices for athletes and active clients and to provide athletes, clients, coaches, and parents with safe guidelines that will allow athletes and clients to achieve and maintain weight and body composition goals. Background: Unsafe weight management practices can compromise athletic performance and negatively affect health. Athletes and clients often attempt to lose weight by not eating, limiting caloric or specific nutrients from the diet, engaging in pathogenic weight control behaviors, and restricting fluids. These people often respond to pressures of the sport or activity, coaches, peers, or parents by adopting negative body images and unsafe practices to maintain an ideal body composition for the activity. We provide athletic trainers with recommendations for safe weight loss and weight maintenance in sport and exercise. Although safe weight gain is also a concern for athletic trainers and their athletes and clients, that topic is outside the scope of this position statement. Recommendations: Athletic trainers are often the source of nutrition information for athletes and clients; therefore, they practices, and methods to change body composition. Body composition assessments should be done in the most scientifically appropriate manner possible. Reasonable and individualized weight and body composition goals should be identified by appropriately trained health care personnel (eg, athletic trainers, registered dietitians, physicians). In keeping with the American Dietetics Association (ADA) preferred nomenclature, this document uses the terms registered dietitian or dietician when referring to a food and nutrition expert who has met the academic and professional requirements specified by the ADA\u27s Commission on Accreditation for Dietetics Education. In some cases, a registered nutritionist may have equivalent credentials and be the commonly used term. All weight management and exercise protocols used to achieve these goals should be safe and based on the most current evidence. Athletes, clients, parents, and coaches should be educated on how to determine safe weight and body composition so that athletes and clients more safely achieve competitive weights that will meet sport and activity requirements while also allowing them to meet their energy and nutritional needs for optimal health and performance

The effect of diet/supplement intake and competitive swimming/gymnastics upon the bone mineral density of collegiate females

The purpose of this pilot study was to determine if there was a relationship between dietary/supplemental intake and competitive activity (swimming and gymnastics), on the bone mineral density of 18-21 year old females. Five swimmers, 4 gymnasts, and 12 control subjects were recruited from the university student body. All subjects completed a 3-day diet/supplement record, 3-day activity record, past calcium intake form, and a medical history form. Bone mineral density (BMD) was measured for the whole body, L1-L4, the proximal femur and body composition by DEXA. Results indicated the control subjects reported a significantly greater percent of the RDA for energy, protein, and carbohydrate than the athletic groups. There were no differences found for bone building nutrients among the three groups. No correlations could be made between diet/supplement intake and BMD. Gymnasts initiated training at an earlier age than swimmers, and were found to be shorter and experience delayed menarche than other groups. Gymnasts had significantly greater whole body BMD than the control subjects, but not significantly greater than the swimmers. Gymnasts also had greater BMD at all sites measured, and significantly greater than the control subjects at the spine L1-L4, and femoral neck. Gymnasts had significantly greater BMD at the femoral neck and total hip than the swimmers. Though not significant, the swimmers had greater BMD at whole body, and spine L1-L4 than the control subjects. As in similar studies, the greater BMD found in the gymnasts can be attributed to their weight bearing exercise. Due to small sample size, conclusions concerning the benefit of swimming on BMD cannot be made from this study

Martial Arts for Health: Translating Research into Practice

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