The aim of this study was to examine the concurrent validity of 2 portable systems for vertical jump (VJ) assessment under field conditions. The VJ flight times assessed using an optical mat (Optojump) and an accelerometer-based (Myotest) system were compared with that of a force platform. The flight times recorded during a countermovement jump (CMJ) were collected from 20 rugby players (n = 86 jumps) concurrently using the 3 tracking systems. Significant bias between the Force platform and either the Optojump (bias = 0.006 ± 0.007; 95% confidence interval [CI] 0.004-0.007 seconds) and Myotest (bias = -0.031 ± 0.021; 95% CI 0.035 to -0.026s; p < 0.0001) occurred. A nearly perfect correlation was found between force platform and Optojump (r = 0.99; 95% CI 0.098-0.99; p < 0.0001). Force platform and Myotest (r = 0.89; 95% CI 0.084-0.93; p < 0.0001) flight times showed very large association. Difference between Optojump and Myotest systems was significant (-0.036 ± 0.021 seconds; 95% CI -0.041 to -0.032; p < 0.0001), which results in Myotest mean flight time being approximately 7.2% longer than the Optojump flight time. The association between Optojump and Myotest was nearly perfect (r = 0.91, 95% CI 0.86-0.94; p < 0.0001). This study showed that the Optojump and Myotest systems possess convergent validity and can be successfully used under field conditions to assess VJ while performing a CMJ. However, caution should be exercised when interpreting data obtained from different portable systems for field measurement.

The purpose of this study is to verify the physiological effect and describe the intensity of training in response to internal and external loads, through Session Rate of Perceived Exertion and Speed High Intensity Distance in Meters reports, on professional soccer players engaged in weekly training (199 Sessions, 43 weeks) and league games (32 official matches). Twenty-two male professional soccer players (n = 22) of the Italian national championship under-19 are involved in this study during the season 2014-2015. Daily, Weekly and Monthly RPE (perceived exertion) Session (Borg CR-10 Scale) is a good indicator of the amount of work done: training time multiplied by perceived effort (TL = Training Time × RPE). With Arbitrary units (a.u.) produced by the individual and used for team-based data analysis, we analyze the intensity produced by workout depending on the working time. Furthermore, by means of global positioning system technology (K-Sport, Montelabbate PU, Italy 10 Hz), we statistically established the existing relationship with high intensity speed distance (> 16 km/h) and session rate of perceived exertion to describe how the internal (represented by the sum of the stresses that the body undergoes an external load; is strictly subjective) and external loads (the objective quantification of the means used in training km routes, running speed, slope, type of recovery), are correlated (r = 0.87, p <0.01, 95% CI). The statistical analysis highlights how these methods are suitable to quantifying the high-intensity work done by the soccer player during the workout and the game.

Purpose: The aim of this study is analyze the training load in élite goalkeepers (GK) during a training week with a new system analysis K-Track (K-TRACK/IMU K-SPORT UNI.STATS, Montecchio, ITA) and verify if the goalkeepers (GK) training program is correct to create specific adaptations and improve performance. K-Track system allows to analyze work time, total workload developed during a session or match, average strength produced, lateral imbalance (left and right), number of vertical jumps, vertical jump accelerations (intensity), number of dives to the right (volume), right dive accelerations (intensity), number of dives to the left (volume) and left dive accelerations (intensity).This parameters it's completely different from other players and it's necessary to have correct information from GK performance. In conclusion how much and how to train the goalkeeper to improve fitness and performance in high-level professional team. Method: Three (n=3) professional goalkeepers were analyzed (age 20.3±1.5 body weight 80.9±7.6 kg; height 188±2.9cm; fat mass 9.4±2.9 %), during 20 workout and 4 official match in season 2019-2020 with K-Track (K-TRACK/IMU K-SPORT UNI.STATS, Montecchio, ITA). Conclusion: This case study has allowed us to highlight which training load is correct for this role during a training week to improve physical performance. In fact, not have specific studies that have analyzed specific parameters for GK, because it is necessary a K-Track device to collect correct information. If we know correct training load, it is possible to improve or reduce exercises intensity and volume. In addition, it is clear that physical and technical-tactical goalkeeper profile is completely different from other players in football.

In recent years, the study of movement analysis with the application of dedicated advanced technologies, such as inertial technologies, has also become essential in scientific research of sports disciplines such as martial arts and combat sports, to better define the real dynamics of technical components in order to adapt the training design. A great number of studies in the literature have focused on the kinematics of circular kick in combat sport and martial arts but a relatively small number have focused on the kinetic and kinematic analysis of Muay Thai and especially its circular kick technique. This study aims to highlight instrumentally the quality of circular kick gesture and through which segmental motor dynamics it achieves its greatest effectiveness, evaluating the accelerations and execution times of the different body segments involved in technical execution itself obviously in a performative sense. It is important to note that the inertial data shows that both knee and ankle have an increasing linear velocity greater than the hip in the preparation and execution phase, while for the angular velocity in the execution phase it is the hip that has higher acceleration than the knee and ankle. These results, therefore, highlight the basic importance of intra-articular and intramuscular coordination processes that allow or not linearity and fluidity of movements that are the basis to obtain maximum intersegmental performance in order to deliver maximum acceleration in the apical point of the shot and thus have the maximum effectiveness of hit and therefore the optimal performance.