Aging Effects on Neuromuscular Activity in Karate Practitioners

Aging leads to a general decline in body functions that affects quality of life. Sports practice is recommended as a means to attenuate the impact of the aging process. The aim of this study was to identify and analyze the neuromuscular activity and its patterns on active karate practitioners and assess the effects of the aging process. Two groups of black belt male karate practitioners, one with nine practitioners over 50 years old and the other with 21 practitioners aged between 20-30 years old performed the frontal kick mae-geri. Kinematic and electromyographic data of five muscles were collected from the right leg. Results showed two distinct periods of muscular activation in the mae-geri performance, with similar muscles activity patterns between groups. Nevertheless, some differences were found in the muscles＇ activity onset and offset, in root mean square and in inter-muscle delay and co-contraction periods. Those differences indicated that aging affects the neuromuscular activity in the mae-geri performance of the oldest karate practitioners. Nevertheless, the results showed that lifelong practice of karate can preserve the quality of the neuromuscular activity in older practitioners when they perform a kick, and this could be associated with benefits to balance control.

Anthropometric Characteristics of Elite Male Taekwondo Players Based on Weight Categories

Purpose The aim of this study was to investigate the anthropometric characteristics of elite taekwondo players based on weight categories,and to determine if the length of the lower extremities might influence player’s success-level.A total of 59 elite male taekwondo players(22.02±3.07 years)participated in this study.Methods All anthropometric assessments were performed according to the standards and methodology of the International Society for Advancement of Kinanthropometry.The 18 anthropometrical variables were measured for each athlete and compared between 7 different weight categories.The players were also divided into two groups(national and international)and the ratios of sitting-height to stature were compared.Results There were significant differences(P<0.05)between weight divisions in stature,body mass index,percentage of body fat,endomorphy,and mesomorphy,which were greater(P<0.05)in heavy weight groups than light weight groups,and ectomorphy,which was greater(P<0.05)in very light weight groups compared with the other weights.There was no significant difference in lean mass index(P>0.05)between weight groups.Sitting height/stature ratio was significantly dif-ferent(P<0.05)between the two groups,where the international group had longer lower extremities than the national group.Conclusion The findings of this study provide a valuable framework to support talent identification programmes and the development of specialised preparatory strategies for different weight divisions with the sport.

Less Aggressive Weight Making Practices in Combat Sport When Recovery Time is Limited:Weight Loss Practices of Pencak Silat Athletes in Singapore

Abstract Weight making behaviours and best practice recommendations for various combat sports have been well documented,how-ever this is not true for Silat athletes.Pre-and post-weigh-in recommendations for other combat sports may not be suitable for Silat due to differences in weigh-in rules.Using a well-established questionnaire,this questionnaire-based cross sectional study examined weight making practices of Silat match athletes(n=102)competing at a national Pencak Silat championship.The 24.5%of athletes engaged in pre-competition weight loss,and the overall Rapid Weight Loss Score(RWLS)was 27.7±8.7,considerably lower than other combat sports.The median age when weight loss began was 17 years,with 32%(n=8)starting such practices under 17 years.Risky weight management practices such as the use of laxatives,diet pills and vomiting were less common than in other combat sports.Coaches and fellow athletes are key influencers of weight making practices,and dietitians were found be an underutilised resource.Appropriate measures to empower coaches and athletes with the knowledge and ability to guide and execute less detrimental weight making practice with the involvement of dietitians are suggested.The study findings provide information to establish Silat-specific dietary strategies to improve health and performance.

Assessment of the Anaerobic Speed Reserve during Specific High-Intensity Exercise in Judo Athletes

Purpose This study aimed to describe self-selected intensity and its relationship to performance during a high-intensity all-out judo protocol,and to verify whether athletes with different anaerobic speed reserve(ASR)perform differently during a high-intensity all-out interval uchi-komi(judo-specific skill).Methods We analyzed the performance of 28 judo athletes as a whole group and divided into groups,according to their ASR.They performed several judo-specific protocols using a specific skill:maximal speed sprint(MSS)and maximal aerobic speed(MAS),and high-intensity intermittent uchi-komi protocol(12×20 s all-out:10 s passive recovery).Results The main results demonstrated a decrease in the number of repetitions and an increase in heart rate across the sets.Athletes with greater ASR performed a higher number of repetitions,compared to the low ASR group,and they were able to exercise at a higher percentage of the MAS(low ASR=126%;SD=13%;high ASR=152%,SD=l9%)and at a lower percentage of MSS compared to the low ASR group(low ASR=84%,SD=7%;high ASR=76%,SD=11%).However,both groups exercised at a similar percentage of their own ASR during the protocol(low ASR=50%,SD=20%;high ASR=53%,SD=19%).Conclusions Athletes with different ASR seem to set their pace at around 50%of their ASR within an all-out uchi-komi pro-tocol.Therefore,the ASR is useful for predicting performance during high-intensity judo-specific interval exercise intervals.