Faigenbaum, AD, Kraemer, WJ, Blimkie, CJR, Jeffreys, I, Micheli, LJ, Nitka, M, and Rowland, TW. Youth resistance training: Updated position statement paper from the National Strength and Conditioning Association. J Strength Cond Res 23(5): S60-S79, 2009-Current recommendations suggest that school-aged youth should participate daily in 60 minutes or more of moderate to vigorous physical activity that is developmentally appropriate and enjoyable and involves a variety of activities (). Not only is regular physical activity essential for normal growth and development, but also a physically active lifestyle during the pediatric years may help to reduce the risk of developing some chronic diseases later in life (). In addition to aerobic activities such as swimming and bicycling, research increasingly indicates that resistance training can offer unique benefits for children and adolescents when appropriately prescribed and supervised (). The qualified acceptance of youth resistance training by medical, fitness, and sport organizations is becoming universal ().Nowadays, comprehensive school-based programs are specifically designed to enhance health-related components of physical fitness, which include muscular strength (). In addition, the health club and sport conditioning industry is getting more involved in the youth fitness market. In the U.S.A., the number of health club members between the ages of 6 and 17 years continues to increase () and a growing number of private sport conditioning centers now cater to young athletes. Thus, as more children and adolescents resistance train in schools, health clubs, and sport training centers, it is imperative to determine safe, effective, and enjoyable practices by which resistance training can improve the health, fitness, and sports performance of younger populations.The National Strength and Conditioning Association (NSCA) recognizes and supports the premise that many of the benefits associated with adult resistance training programs are attainable by children and adolescents who follow age-specific resistance training guidelines. The NSCA published the first position statement paper on youth resistance training in 1985 () and revised this statement in 1996 (). The purpose of the present report is to update and clarify the 1996 recommendations on 4 major areas of importance. These topics include (a) the potential risks and concerns associated with youth resistance training, (b) the potential health and fitness benefits of youth resistance training, (c) the types and amount of resistance training needed by healthy children and adolescents, and (d) program design considerations for optimizing long-term training adaptations. The NSCA based this position statement paper on a comprehensive analysis of the pertinent scientific evidence regarding the anatomical, physiological, and psychosocial effects of youth resistance training. An expert panel of exercise scientists, physicians, and health/physical education teachers with clinical, practical, and research expertise regarding issues related to pediatric exercise science, sports medicine, and resistance training contributed to this statement. The NSCA Research Committee reviewed this report before the formal endorsement by the NSCA.For the purpose of this article, the term children refers to boys and girls who have not yet developed secondary sex characteristics (approximately up to the age of 11 years in girls and 13 years in boys; Tanner stages 1 and 2 of sexual maturation). This period of development is referred to as preadolescence. The term adolescence refers to a period between childhood and adulthood and includes girls aged 12-18 years and boys aged 14-18 years (Tanner stages 3 and 4 of sexual maturation). The terms youth and young athletes are broadly defined in this report to include both children and adolescents.By definition, the term resistance training refers to a specialized method of conditioning, which involves the progressive use of a wide range of resistive loads and a variety of training modalities designed to enhance health, fitness, and sports performance. Although the term resistance training, strength training, and weight training are sometimes used synonymously, the term resistance training encompasses a broader range of training modalities and a wider variety of training goals. The term weightlifting refers to a competitive sport that involves the performance of the snatch and clean and jerk lifts.This article builds on previous recommendations from the NSCA and should serve as the prevailing statement regarding youth resistance training. It is the current position of the NSCA that:

Youth resistance training: updated position statement paper from the national strength and conditioning association.

Analysis of Contingency Tables

Objective: To compare five martial arts with respect to injury outcomes. Methods: A one year retrospective cohort was studied using an injury survey. Data on 263 martial arts participants (Shotokan karate, n  =  114; aikido, n  =  47; tae kwon do, n  =  49; kung fu, n  =  39; tai chi, n  =  14) were analysed. Predictor variables included age, sex, training frequency (⩽3 h/week v >3 h/week), experience ( v ⩾3 years), and martial art style. Outcome measures were injuries requiring time off from training, major injuries (⩾7 days off), multiple injuries (⩾3), body region, and type of injury. Logistic regression was used to determine odds ratios (OR) and confidence intervals (CI). Fisher’s exact test was used for comparisons between styles, with a Bonferroni correction for multiple comparisons. Results: The rate of injuries, expressed as percentage of participants sustaining an injury that required time off training a year, varied according to style: 59% tae kwon do, 51% aikido, 38% kung fu, 30% karate, and 14% tai chi. There was a threefold increased risk of injury and multiple injury in tae kwon do than karate (p 3 h/week was also a significant predictor of injury (p Conclusions: There is a higher rate of injury in tae kwon do than Shotokan karate. Different martial arts have significantly different types and distribution of injuries. Martial arts appear to be safe for young athletes, particularly those at beginner or intermediate levels.

https://bjsm.bmj.com/content/bjsports/39/1/29.full.pdf

Injuries in martial arts: a comparison of five styles

This review focuses on the most important physical and physiological characteristics of karate athletes from the available scientific research. It has been established that karate’s top-level performers require a high fitness level. Top-level male karate athletes are typified by low body fat and mesomorphic-ectomorphic somatotype characteristics. Studies dealing with body composition and somatotype of females are scarce. Aerobic capacity has been reported to play a major role in karate performance. It prevents fatigue during training and ensures the recovery processes during rest periods between two subsequent bouts of fighting activity within a fight and between two consecutive matches. It has been established that there is no significant difference between male and female kata (forms) and kumite (sparring/combat) athletes with regard to aerobic performance. Nevertheless, further studies are needed to support these findings. Concerning anaerobic performance, there is a difference in maximal power explored by the force-velocity test between national and international level karatekas (karate practitioners) but, for the maximum accumulated oxygen deficit test there is no difference between them. Muscle explosive power plays a vital role in a karateka’s capacity for high-level performance. However, it has been revealed that vertical jump performance, maximal power and maximal velocity differed between national- and international-level karatekas. Moreover, it has been reported that karate performance relies more on muscle power at lower loads rather than higher ones. Thus, karate’s decisive actions are essentially dependent on muscle explosive power in both the upper and lower limbs. With regard to dynamic strength, limited research has been conducted. The maximal absolute bench press, half-squat one-repetition maximum and performance of isokinetic tasks differed significantly between highly competitive and novice male karatekas. Studies on female karate athletes do not exist. Concerning flexibility, which is important for the execution of high kicks and adequate range of action at high speeds, it has been demonstrated that karate athletes’ ranges of bilateral hip and knee flexion are greater compared with non-karate athletes. Finally, reaction time is a crucial element in karate because high-level performance is based essentially on explosive techniques. A significant difference in the choice reaction time between high-level and novice karatekas exists. Further research is needed concerning the physiological characteristics of female karatekas, the differences between kata and kumite athletes and variations based on weight categories.

/pdf/physical-and-physiological-profile-of-elite-karate-athletes-2iy1t51393.pdf

Physical and Physiological Profile of Elite Karate Athletes

Background: The duration and vigour of physical exercise are widely considered to be critical elements that may positively or negatively affect physical health and immune response. Objectives: To investigate the effect of a 12 week programme of regular tai chi chuan exercise (TCC) on functional mobility, beliefs about benefits of exercise on physical and psychological health, and immune regulation in middle aged volunteers. Methods: This quasi-experimental research design involving one group with testing before and after the programme was conducted to measure the effect of 12 weeks of TCC exercise in 14 men and 23 women from the normal community. Results: Regular TCC exercise had a highly significant positive effect on functional mobility (p  =  0.001) and beliefs about the health benefits of exercise (p  =  0.013) in the 37 participants. Total white blood cell and red blood cell count did not change significantly, but a highly significant (p Conclusions: A 12 week programme of regular TCC exercise enhances functional mobility, personal health expectations, and regulatory T cell function.

/pdf/regular-tai-chi-chuan-exercise-enhances-functional-mobility-2kzb2nsnzx.pdf

Regular tai chi chuan exercise enhances functional mobility and CD4CD25 regulatory T cells

http://www.budopoint.de/en/science/articles/Karate%20injuries%20in%20children%20and%20adolecents.pdf

Karate injuries in children and adolescents

The effect of 6 months of twice weekly karate training on flexibility, balance, and strength was evaluated in 14 boys who perform karate as beginners (age M = 10.3 ± 1.8) and a group of the same age who had never been involved in martial arts (n = 10; age M = 10.9 ± 1.4). All subjects were pretested and posttested on the following: flexibility of upper extremity (shoulder), hamstrings and quadriceps; strength, including handgrip strength and concentric flexion/extension of quadriceps; and balance, with eyes either open or closed. After 6 months, the tests were evaluated and compared by groups. The results showed the karate group made significant gains on quadriceps flexibility and balance with eyes closed. By improving flexibility, balance, and strength, karate improves three of the basic fitness components that are very important for preventing sport injuries in the growing years.

The Effect of Karate Training on Flexibility, Muscle Strength, and Balance in 8- to 13-Year-Old Boys

ObjectiveTo study risk factors for injury in karate and to establish safety recommendations.DesignCross-sectional survey of karate injuries.SettingShotokan karate clubs in Boston, Massachusetts, Dallas, Texas, and Winnipeg, Manitoba, Canada.ParticipantsAll athletes training at each club received sur

Safety recommendations in Shotokan karate.

Objective: To identify risk factors for injury in rhythmic sportive gymnastics and to provide recommendations for reducing the risk of injury. Methods: A one-year retrospective survey of injuries in twenty national-level rhythmic gymnasts (ages 14.8 to 18.8 years; mean age 17.1 years). Hours of rhythmic gymnastics (RG) training per week, minutes of stretching per day, and hours of conditioning per week, were analyzed as potential risk factors for injury. Main outcome measures were injuries that required time off, major injuries (at least 7 days off), injuries to muscle-tendon units, and fractures. Results: Thirteen (65%) of 20 gymnasts sustained timeloss injuries, and 4 gymnasts (20%) reported major injuries. Seventeen (85%) gymnasts reported muscle-tendon unit injuries and 5 (25%) suffered fractures. Sixteen (80%) of the gymnasts reported back pain or stress fractures of the back, 8 of whom required time off training. One gymnast (5%) incurred a concussion. Logistic regression indicated that rhythmic gymnastics training and stretching were associated with muscle-tendon unit injury. On multivariate analysis, stretching was found to be the only independent predictor of muscle-tendon unit injuries with each additional minute lowering the risk by approximately 10% (p ≤ 0.01). Conditioning and stretching were both independent predictors of fractures. The risk of fracture was estimated to increase by over 60% for each additional hour of weekly conditioning (odds ratio = 1.62; p = 0.03) and decrease by almost 20% for each additional minute of daily stretching (odds ratio = 0.81; p = 0.04). None of the variables studied were predictive of back pain or injury. Conclusions: Injuries in rhythmic gymnastics may be reduced by increasing the amount of time spent stretching per day (at least 40 minutes), and limiting conditioning to a maximum of 6 hours per week.

/pdf/injuries-and-training-recommendations-in-elite-rhythmic-w6hav7hv6d.pdf

Mariona A. Violan

Papers

Injuries in martial arts: a comparison of five styles

Karate injuries in children and adolescents

The Effect of Karate Training on Flexibility, Muscle Strength, and Balance in 8- to 13-Year-Old Boys

Safety recommendations in Shotokan karate.

Injuries and training recommendations in elite rhythmic gymnastics