An exhaustive review has been made to filter the studies that have analyzed muscle function though tensiomyography (TMG) with elite or well-trained athletes. The results of this review indicate that the several protocols used in athletes to find the displacement-time curve with greater maximum radial muscle displacement showed a good-excellent reliability. TMG has been used to characterize athletes’ muscles contractile properties from specific sports disciplines, although there are very few sports that have been deeply analyzed. TMG seems to be useful to determine changes in muscles contractile properties after stimuli of competition, training or recovery. These changes have been strongly related with the fatigue produced after an effort. In addition, TMG parameters could be used to control training effects during a specific period or throughout the season being also a very useful tool to individualize athletes training loads. In this sense, it also seems to provide sports performance information in cyclic sports by relating some TMG parameters with performance indicators. On the other hand, the TMG-BCM algorithm has been used as a lateral and functional symmetry measure and as a monitoring tool for injury prevention and recovery. However, it seems to be no clear criterion that determines asymmetry degree, nor established contractile properties values as a reference to prevent or recover sports injuries. Despite the utility shown in these fields, there are still very few sports analyzed and it is really necessary to continue advancing in the knowledge of the contractile properties behavior, such as the effects of athletes’ training, competitions and injuries and even in the parameters interpretation obtained with the TMG.

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Draft-legal triathlons are the main short-distance races worldwide and are those on which talent-identification programs are usually focused. Performance in these races depends on multiple factors; however, many investigations do not focus on elite triathletes. Therefore, the aim of this narrative review was to carry out a systematic literature search to define the elite female and male triathlete profiles and their competition demands in draft-legal triathlons. This will allow us to summarize the main determinant factors of high-level triathletes as a basis for talent detection. A comprehensive review of Web of Science and Scopus was performed using the search strategy: Triathl* and (performance or competition or profile) and (elite or professional or “high performance” or “high level” or talent). A total of 1325 research documents were obtained, and after screening following the criteria, only 83 articles were selected. After data synthesis, elite triathlete aspects such as age, physiological, anthropometric, and psychosocial profile or competition demands were studied in the scientific literature. Thus, it is essential that when implementing talent identification programs, these factors must be considered. However, constant updating is needed due the continuous regulatory changes and the need of triathletes to adapt to these new competition demands.

The development of lateral asymmetries in athletes could have an influence on performance or injuries. The aim of this study was to determine the within-day reliability of the symmetry tests and the performance tests, and explore the relationship between them. Eighteen male volleyball players (18.1 ± 2.1 years) participated in this study. Seven lateral symmetry assessments were used, namely: lateral symmetry through tensiomyography (LS), active knee extension (AKE), Y-balance test (YBT), muscular electrical activity in attack jump (MEA-AJ), single-leg squat jump (SLSJ), triple hop test for distance (THTD), and bilateral maximum repetition in leg press (1RMSL); and three volleyball performance tests, namely: the T-test, counter-movement jump (CMJ), and attack jump (AJ). Three in-day measurements were taken from each volleyball player after the recovery was completed. The reliability was calculated through the intraclass correlation coefficient and the coefficient of variation, and the relationship was calculated through Pearson’s bivariate correlation coefficient (p < 0.05). The results indicate that AKE, YBT, and LS are the symmetry tests with increased reproducibility. THTD correlates positively with the AKE test and 1RMSL test, and a greater symmetry in the YBT correlates with a greater performance in the CMJ and AJ performance tests. In conclusion, AKE, LS, and YBT are the best tests to determine, with reliability, the asymmetries in volleyball players, and a greater symmetry in the YBT seems to influence the height of bilateral vertical jump.

The aim of this study was to determine de acute effect of an 8-weeks specific hamstring flexibility training on junior canoeist during the competition season. Sixteen canoeists participated, divided into 3 groups: 5 in Experimental Group 1 (EG1), 5 in Experimental Group 2 (EG2) and 6 in a Control Group (CG). The EG1 underwent a supervised program consisted by Simple Static Stretching, Dynamic Static Stretching and P.N.F. while the EG2 performed a program without P.N.F. and no supervision. Two measurements were performed to analyze the effect on the knee joint ROM and trunk flexion; neuromuscular and contractile properties in Biceps Femoris (BF) and Semitendinosus (ST) muscles; maximum power and average speed in lower limbs. A mixed-design factorial analysis of variance (p <0.05) was performed and the effect size was calculated. The results show significant improvements (p <0.05) in both legs for knee joint ROM and trunk flexion in EG1 (8.9% and 25.5%; 5.7% and 20.9% in right and left leg respectively) and EG2 (6.7% and 22%; 3.9% and 24.4%), only EG1 improved muscular stiffness in BF (27.4% left leg) and ST (20.5% and 24.3%), and lateral symmetry in BF (49%) without decreasing average speed in lower limbs. All improvements have a large effect size. In conclusion, it is suggested that a supervised hamstring flexibility program performed concurrently during a canoeist competition season can produce an increase in the knee joint ROM and trunk flexion, without negative repercussions in contractile and neuromuscular capacities, maximum power and average velocity in lower limbs.