The aim of the present study was to compare the effects of different warm-up interventions on jump, sprint and agility performance in collegiate soccer players. Twenty-one healthy male college soccer players (age: 20.14 ± 1.65 years; body height: 179.9 ± 8.34 cm; body mass: 74.4 ± 13.0 kg; % body fat: 9.45 ± 4.8) participated in the study. Subjects underwent four different randomized warm-up protocols separated by at least 48 hours. The warm-up schemes were: 1. no conditioning contraction protocol (NCC); 2. dynamic stretching (DS); 3. prolonged intermittent low-intensity isometric exercise (ST); and, 4. ST with an additional external load equal to 30% of body weight (ST + 30% BW). All interventions were preceded by a general warm-up. Results from one-way repeated measures ANOVA demonstrated a significant difference in countermovement jump (CMJ) at F(3,60) = 10.2, ηρ2 = 0.337, p < 0.01. Post hoc analysis revealed a significant difference in CMJ performance in DS when compared to NCC and ST + 30% BW. No significant difference in CMJ was observed between DS and ST. CMJ scores in NCC, ST, and ST + 30% BW were non-significant. There was a significant difference in speed; F(3, 60) = 6.61, ηρ2 = 0.248, p < 0.01. Post hoc analysis revealed significantly better time in DS than NCC and ST. However, no difference in speed was observed between DS and ST + 30% BW. Similarly, speed was similar in NCC, ST and ST + 30% BW. A significant difference in agility performance was also observed; F(3, 60) = 24.1, ηρ2= 0.546, p < 0.01. Post hoc analysis revealed significantly greater performance gains in DS than NCC. No significant difference in agility was observed in DS, ST and ST + 30% BW. In conclusion, a prolonged intermittent low-intensity isometric protocol using bodyweight only showed similar benefits with dynamic stretching in countermovement jump performance. When the same isometric condition with additional load equal to 30% of bodyweight was applied, effects in speed and agility were similar to dynamic stretching.

Reducing bodyweight within a short-time participating in kicking combat sports can adversely affect health. This study's aim creating an improved model to categorize athletes in kicking combat sports. The investigation focused on 795 athletes (11-24 years), participating in the Croatian National Taekwondo Championship. The sample included athletes from both sexes (371 males), cadets (n = 325), juniors (n = 247) and seniors (n = 223). Data were collected during the preparatory period and prior to the athletes competing, using a bioelectrical impedance analysis device. According to current categorization rules, athletes are categorized by arbitrarily determined ranges in bodyweight, whereas, in this current study, the authors have devised an improved model, based on body height and the analysis of data collected. The difference in coefficients between the official model and the proposed, improved categorization method in terms of body height (2.70 and 0.71, respectively), showed that the improved model homogenized athletes almost four times more than the official model, reducing the maximal difference in body height from 29 to 9 cm within specific categories. Proposed, improved model had same number of categories as the official structure and directly homogenized differences in height within a category up to a 3-cm maximum for the middle categories and a 9-cm maximum on the periphery of the bands. We expect this improved combat sports categorization model will indirectly reduce differences between other longitudinal body dimensions within categories (thus making match results less predictable) as well as reduce bodyweight manipulation potentially endangering athletes' health.

Background:The application of whole body vibration (WBV) as a warm-up scheme has been receiving an increasing interest among practitioners.Objectives:The aim of this study was to determine the effect of loaded and unloaded WBV on countermovement jump, speed and agility.Patients and Methods:Twenty-one healthy male college football players (age: 20.14 ± 1.65 years; body height: 179.9 ± 8.34 cm; body mass: 74.4 ± 13.0 kg; % body fat: 9.45 ± 4.8) underwent randomized controlled trials that involved standing in a half squat position (ST), ST with 30% of bodyweight (ST + 30%), whole body vibration at f = 50 Hz, A = 4 mm (WBV), and WBV with 30% bodyweight (WBV + 30% BW) after a standardized warm-up. Post measures of countermovement jump, 15-m sprint, and modified t-test were utilized for analyses.Results:One way repeated measures ANOVA revealed a significant difference in the countermovement jump performance, F (3, 60 = 9.06, η2 = 2.21, P = 0.000. Post-hoc showed that WBV + 30% BW posted significant difference compared to (P = 0.008), ST + 30% BW (P = 0.000) and WBV (P = 0.000). There was also a significant difference in the sprint times among interventions, F (3, 60) = 23.0, η2 = 0.865, P = 0.000. Post hoc showed that WBV + 30% BW displayed significantly lower time values than ST (P = 0.000), ST + 30% BW (P = 0.000) and WBV (P = 0.000). Lastly, there was a significant difference in the agility performance across experimental conditions at F(2.01, 40.1) = 21.0, η2 = 0.954, P = 0.000. Post hoc demonstrated that WBV have lower times than ST (P = 0.013). Also, WBV + 30% BW posted lower times compared to ST (P = 0.000), ST + 30% (P = 0.000) and WBV (P = 0.003).Conclusions:Additional external load of 30% bodyweight under WBV posted superior gains in countermovement jump, speed and agility compared to unloaded WBV, loaded non-WBV and unloaded non-WBV interventions.

Post-exercise recovery is a complex process involving a return of performance and a physiological or perceptual feeling close to pre-exercise status. The hypothesis of this study is that the device investigated here is effective in evaluating the recovery state of professional cyclists in order to plan effective training. Ten professional male cyclists belonging to the same team were enrolled in this study. Participants performed a 7-day exercise program [D1, D4, and D7: low-intensity training; D2 and D5: passive recovery; D3: maximum oxygen consumption (VO 2Max) test (for maximum mechanical power assessment only); and D6: constant load test]. During the week of monitoring, each morning before getting up, the device assessed each participant's so-called Organic Readiness {OR [arbitrary unit (a.u.)]}, based on blood pressure (BP), heart rate (HR), features of past exercise session, and following self-perceived condition. Based on its readings and algorithm, the device graphically displayed four different colors/values, indicating general exercise recommendations: green/3 = "you can train hard," yellow/2 = "you can train averagely," orange/1 = "you can train lightly," or red/0 = "you should recover passively." During the week of research, morning OR values and Bonferroni post-hoc comparisons showed significant differences between days and, namely, values (1) D2 (after low intensity training) was higher than D4 (after VO 2Max test; P = 0.033 and d = 1.296) and (2) D3 and D6 (after passive recovery) were higher than D4 (after VO 2Max test; P = 0.006 and d = 2.519) and D5 (after low intensity training; P = 0.033 and d = 1.341). The receiver operating characteristic analysis area under curve (AUC) recorded a result of 0.727 and could differentiate between D3 and D4 with a sensitivity and a specificity of 80%. Preliminarily, the device investigated is a sufficiently effective and sensitive/specific device to assess the recovery state of athletes in order to plan effective training.

The main purpose of this study was to determine the body composition and anthropometric reference values of male and female junior Croatian taekwondo competitors according to official weight category. Additional aim of the study was to identify possible differences in variables between the weight categories. The sample comprised 247 junior participants of the national taekwondo championships divided into male (N=121) and female (N=126). The variable sample was defined by a set of 8 measurements: Body height (cm), Body mass (kg), Body mass index, Body fat (%), Body fat (kg), Muscle mass (kg), Lean body mass (kg) and Total body water (%). Results confirm previous studies proving that younger taekwondo practitioners have higher levels of body fat than their more experienced peers (seniors). Significant differences were only found between lean and heavy categories. Male junior taekwondo athletes show total body water percentages from 57.4 to 74.8 %, with significantly lower percentages in higher weight categories, while female athletes in heigher categories demonstrate a worrying level of hydration status, therefore endangering their performance and overall health. As the first paper that investigates the reference values of junior taekwondo athletes but based on official weight categories it is especially important as each weight category warrant different body composition requirements, as seen from significant differences across different variables. Future studies should include motor abilities inspection throughout the weight categories and possible use of calculation of metabolic age.