Muscle Contraction Adaptations in Top-Level Karate Athletes Assessed by Tensiomyography.

BACKGROUND: This paper aimed to compare the involuntary stimulated neuromuscular response of thigh muscles in top-level karate athletes and recreational groups. METHODS: The study included 13 male karate athletes (KAs) and 14 non-athlete male individuals (NAs). Tensiomyographic (TMG) measurements were obtained from the rectus femoris (RF), vastus medialis (VM), vastus lateralis (VL), biceps femoris (BF) and semitendinosus (ST). RESULTS: Statistically significant differences were observed between KAs and NAs in knee extensor/flexor delay time (Td), contraction time (Tc), total contraction time (Tct), maximal radial displacement of the muscle belly (Dm) and rate of muscle tension development (RMTD). On a group level, KA dominant-leg extensors and flexors and also non-dominant-leg knee flexors had significant differences when compared to NA. Tct is a TMG parameter in which the KAs and NAs differ the most in the case of the knee extensors, while flexor muscles differ the most in the RMTD parameter. CONCLUSIONS: The lower Tct values indicate an improved ability of top-level karateka to make fast contractions of the agonist muscles. KAs' higher RMTD values suggest on strength characteristics needed in breaking actions of the antagonist muscles. Existence of contraction-relaxation-contraction neuromuscular pattern in the RF muscle suggests on implementation of training strategies that involves both rapid muscle contractions and relaxations.

Accuracy of Body Mass Index and Obesity Status in Police Trainees.

The first aim of this study was to compare body mass index (BMI) (indirect method) classification with the body fat percent (PBF) (direct method) and to determine how BMI classifies subjects with different levels of skeletal muscle mass percent (PSMM). The second aim was to determine the prevalence of overweight and obesity status among police trainees (PTs). A total of 103 male PTs participated in this research: age = 21.46 ± 0.64 years, body mass (BM) = 75.97 ± 8.10 kg, body height (BH) = 174.07 ± 6.31 cm, BMI = 25.05 ± 2.12 kg/m2. The InBody 370 multichannel bioelectrical impedance analysis (BIA) measured body composition. Study results indicated that muscular PTs could be misclassified as overweight and that PBF identified more subjects as obese. Namely, three PTs were obese according to BMI, while 13 were obese according to PBF. The information provided by this research could be used to help professionals understand the importance of measuring body composition, and the inaccuracies in BMI classification. In conclusion, whenever possible PSMM and PBF should replace the utilization of BMI to screen overweight and obesity in PTs. Agencies may think of using BIA as non-invasive, quick and inexpensive measurement tool.

Impact of a 12-Week Postgraduate Training Course on the Body Composition and Physical Abilities of Police Trainees.

ABSTRACT: Cvorovic, A, Kukic, F, Orr, RM, Dawes, JJ, Jeknic, V, and Stojkovic, M. Impact of a 12-week postgraduate training course on the body composition and physical abilities of police trainees. J Strength Cond Res 35(3): 826-832, 2021-The main objective of this study was to determine the effects of a 12-week physical training program on police trainees at the Abu Dhabi Police College. Anthropometric and fitness testing data for 325 healthy trainees, enrolled in an academic course for qualification as a police officer, were analyzed. The trainees were tested 3 times, during the initial (week 1), midpoint (week 7), and final testing (week 13) phases of the training program. The tested variables included anthropometry (body mass [BM]), body composition (body mass index [BMI]; waist circumference [WC]; waist-to-height ratio [WHtR]), upper-body muscular endurance (1-minute push-up [PU]), trunk muscular endurance (1-minute sit-up [SU]), and aerobic endurance (2.4-km run [RUN]). A 1-way analysis of variance with post hoc Bonferroni adjustment was performed to investigate the changes in anthropometry and fitness across the 3 testing periods with percentages of change calculated at each testing stage. Alpha levels were set at 0.05 a priori. Statistically significant differences (range of p values from p < 0.001 to p < 0.05) were found in all tested variables (BM, BMI, WC, WHtR, PU, SU, and RUN) and between all testing stages (initial, midpoint, and final). A progressive physical training program that incorporates mesocycles and midpoint evaluations can have a positive impact on the fitness of trainees even when undergoing a busy academy program.