Soccer is the most popular sport in the world and is performed by men and women, children and adults with different levels of expertise. Soccer performance depends upon a myriad of factors such as technical/biomechanical, tactical, mental and physiological areas. One of the reasons that soccer is so popular worldwide is that players may not need to have an extraordinary capacity within any of these performance areas, but possess a reasonable level within all areas. However, there are trends towards more systematic training and selection influencing the anthropometric profiles of players who compete at the highest level. As with other activities, soccer is not a science, but science may help improve performance. Efforts to improve soccer performance often focus on technique and tactics at the expense of physical fitness. During a 90-minute game, elite-level players run about 10 km at an average intensity close to the anaerobic threshold (80-90% of maximal heart rate). Within this endurance context, numerous explosive bursts of activity are required, including jumping, kicking, tackling, turning, sprinting, changing pace, and sustaining forceful contractions to maintain balance and control of the ball against defensive pressure. The best teams continue to increase their physical capacities, whilst the less well ranked have similar values as reported 30 years ago. Whether this is a result of fewer assessments and training resources, selling the best players, and/or knowledge of how to perform effective exercise training regimens in less well ranked teams, is not known. As there do exist teams from lower divisions with as high aerobic capacity as professional teams, the latter factor probably plays an important role. This article provides an update on the physiology of soccer players and referees, and relevant physiological tests. It also gives examples of effective strength- and endurance-training programmes to improve on-field performance. The cited literature has been accumulated by computer searching of relevant databases and a review of the authors' extensive files. From a total of 9893 papers covering topics discussed in this article, 843 were selected for closer scrutiny, excluding studies where information was redundant, insufficient or the experimental design was inadequate. In this article, 181 were selected and discussed. The information may have important implications for the safety and success of soccer players and hopefully it should be understood and acted upon by coaches and individual soccer players.

http://carlocapelli.it/ftp/didattica/master calcio/bibliografia_essenziale/stolen_et_al_2005.pdf

Physiology of Soccer: An Update

Exercise Metabolism and the Molecular Regulation of Skeletal Muscle Adaptation

Exercise Physiology: Energy, Nutrition and Human Performance

Global trends in insufficient physical activity among adolescents: a pooled analysis of 298 population-based surveys with 1·6 million participants.

An ever-growing volume of peer-reviewed publications speaks to the recent and rapid growth in both scope and understanding of exercise immunology. Indeed, more than 95% of all peer-reviewed publications in exercise immunology (currently >2, 200 publications using search terms "exercise" and "immune") have been published since the formation of the International Society of Exercise and Immunology (ISEI) in 1989 (ISI Web of Knowledge). We recognise the epidemiological distinction between the generic term "physical activity" and the specific category of "exercise", which implies activity for a specific purpose such as improvement of physical condition or competition. Extreme physical activity of any type may have implications for the immune system. However, because of its emotive component, exercise is likely to have a larger effect, and to date the great majority of our knowledge on this subject comes from exercise studies.

Position statement. Part one: Immune function and exercise.

The British Association of Sport and Exercise Sciences (BASES) Molecular Exercise
Physiology Interest Group has produced a position stand to advise on ethical and
other issues associated with genetic research in sport and exercise science. This
article is an updated summary of the position stand. The heritability of sport and
exercise-related traits such as maximal oxygen uptake, muscle fibre composition
and trainability is often approximately 50%. Little is known about the variations in
DNA responsible and a major aim of current research is to identify the variations
in DNA (or genetic loci) that determine heritable traits. Identifying the genetic
loci will also inform us about the mechanisms that regulate a trait and could be
used to develop applications such as genetic performance tests or genetic screens
for individuals at high risk of sudden death during sport, for example, due to a
gene mutation related to cardiac function. Another application could be to use
genetic tests to prescribe personalised training or exercise therapy programmes
for athletes or patients, respectively. Serious ethical concerns are associated with
genetic testing especially when such testing is performed on embryos or minors,
requested by others such as parents, coaches or physicians and when it is used
to discriminate against athletes, for example by selecting squad athletes on the
basis of genetic performance tests. Recommendations from the position stand
include: (i) Scientists should be aware of the ethical implications of their work
and engage knowledgably in public debates; (ii) genetic testing in the sport and
exercise context (with the possible exception of preparticipation risk screening)
should be confined to mature individuals who fully understand the relevant issues
and a system of counselling should be introduced; (iii) pre-participation genetic
risk screening should not be obligatory and the confidentiality of such testing
should be ensured.

Genetic research and testing in sport and exercise science: a summary of the BASES position stand.

Although multiple nutrients have shown protective effects with regard to preserving muscle function, the recommended amount of dietary protein and other nutrients profile on older adults for maintenance of high muscle mass is still debatable. The aims of this paper were to: (1) identify dietary differences between older women with low and high relative skeletal muscle mass, and (2) identify the minimal dietary protein intake associated with high relative skeletal muscle mass and test the threshold ability to determine an association with skeletal muscle phenotypes. Older women (n = 281; 70 ± 7 years, 65 ± 14 kg), with both low and high relative skeletal muscle mass groups, completed a food questionnaire. Skeletal muscle mass, fat-free mass (FFM), biceps brachii thickness, vastus lateralis anatomical cross-sectional area (VLACSA), handgrip strength (HGS), maximum elbow flexion torque (MVCEF), maximum knee extension torque (MVCKE), muscle quality (HGS/Body mass), and fat mass were measured. Older women with low relative skeletal muscle mass had a lower daily intake of protein, iodine, polyunsaturated fatty acid (PUFA), Vit E, manganese, milk, fish, nuts and seeds (p < 0.05) compared to women with high relative skeletal muscle mass. The minimum required dietary protein intake for high relative skeletal muscle mass was 1.17 g/kg body mass/day (g/kg/d) (sensitivity: 0.68; specificity: 0.62). Women consuming ≥1.17 g/kg/d had a lower BMI (B = −3.9, p < 0.001) and fat mass (B = −7.8, p < 0.001), and a higher muscle quality (B = 0.06, p < 0.001). The data indicate that to maintain muscle mass and function, older women should consume ≥1.17 g/kg/d dietary protein, through a varied diet including milk, fish and nuts that also contain polyunsaturated fatty acid (PUFA) and micronutrients such as iodine, Vit E and manganese.

Dietary Protein Requirement Threshold and Micronutrients Profile in Healthy Older Women Based on Relative Skeletal Muscle Mass.

Compared to sprint/power and endurance sports, the genetic contribution to success in sports that require a mixture of anaerobic and aerobic qualities has received relatively limited attention. This chapter evaluates research findings on the potential genetic variants influencing the team sports athletic status and the key factors for team sports performance, with particular emphasis on football (soccer) and rugby. Despite the great potential of the genetic studies in team sports and some promising progress recently made, there is very much more yet to be discovered than is understood at present. So far, only 10 genetic markers associated with team sports athlete status have been identified, and replication studies are needed to confirm those associations. In view of the foregoing, large collaborative projects with sound experimental designs (e.g., clearly defined phenotypes, consideration, and control of sources of variability, and necessary replications) are needed to improve understanding in this area.

Genetics of team sports

To the Editor: We read with interest the recent article on the topic of the angiotensin-converting enzyme (ACE) gene by Fuentes and colleagues ([2][1]). We see some value in aspects of their study, for example, as an investigation of the effect of the ACE insertion (I)/deletion (D) polymorphism on

ACE gene, physical activity, and physical fitness.

This is the first article to review the physical and physiological characteristics required for elite rugby performance within both Rugby Union (RU) and Rugby League (RL). Anthropometric characteristics such as height and mass, plus physiological characteristics such as speed and muscular strength, have previously been advocated as key discriminators of playing level within rugby. This review identifies key physical and physiological properties required for elite performance in rugby and attempts to explain why they are required. There are differences between competitive standards such that, at the elite level, athletes are heaviest (RU forwards ~108 kg, backs ~94 kg; RL forwards ~104 kg, backs ~95 kg) with lowest % body fat (RU forwards ~16%, backs ~14%; RL forwards ~14%, backs ~11%), they have most fat-free mass and are strongest (Back squat: RU forwards ~165 kg, backs ~145 kg; RL forwards ~188 kg, backs ~ 168 kg. Bench press: RU forwards ~125 kg, backs ~111 kg; RL forwards ~119 kg, backs ~113 kg) and fastest (10 m: RU forwards ~1.85 s, backs ~1.73 s; 10 m RL forwards ~1.72 s, backs ~1.66 s). We also have unpublished data that indicate contemporary RU athletes have less body fat and are stronger than the published data suggest. Regardless, well-developed speed, agility, lower-body power and strength characteristics are vital for elite performance, probably reflect both environmental (training, diet, etc.) and genetic factors, distinguish between competitive levels and are therefore important determinants of elite status in rugby.

Alun G. Williams

Papers

Genetic research and testing in sport and exercise science: a summary of the BASES position stand.

Dietary Protein Requirement Threshold and Micronutrients Profile in Healthy Older Women Based on Relative Skeletal Muscle Mass.

Genetics of team sports

ACE gene, physical activity, and physical fitness.

The Anthropometric and Physiological Characteristics of Elite Rugby Athletes