AcknowledgementsWe are very grateful to the athletes of the Escola do Movimento Track and Field club for their involvement in the study. The authors declare that they have no conflict of interest. Movement velocity as a measure of exercise intensity in three lower limb exercisesMovement strength velocity and intensity KEY WORDS: Resistance training, movement velocity, strength. ABSTRACTThe purpose of this study was to investigate the relationship between movement velocity and relative load in three lower limbs exercises commonly used to develop strength: Leg Press, Full Squat, and Half Squat. The percentage of one Repetition Maximum (%1RM) has typically been used as the main parameter to control resistance training, however more recent research has proposed movement velocity as an alternative.Fifteen participants performed a load progression with a range of loads until they reached their one repetition maximum (1RM). Maximum instantaneous velocity (Vmax) and mean propulsive velocity (MPV) of the knee extension phase of each exercise were assessed.For all exercises, a strong relationship between Vmax and the %1RM was found: Leg Press (r 2 adj =0.96; 95% CI for slope is [-0.0244 Results indicate that it is possible to determine an exercise-specific %1RM by measuring movement velocity for that exercise.

AimsThe purpose of this study was to compare the effects of hamstring eccentric (NHE) strength training versus sprint training programmed as complements to regular soccer practice, on sprint performance and its mechanical underpinnings, as well as biceps femoris long head (BFlh) architecture. MethodsIn this prospective interventional control study, sprint performance, sprint mechanics and BFlh architecture variables were compared before versus after six weeks of training during the first six preseason weeks, and between three different random match-pair groups of soccer players: "Soccer group" (n = 10), "Nordic group" (n = 12) and "Sprint group" (n = 10).The results suggest that sprint training was superior to NHE in order to increase BFlh fascicle length although only the sprint training was able to both provide a preventive stimulus (increase fascicle length) and at the same time improve both sprint performance and mechanics. Further studies with advanced imaging techniques are needed to confirm the validity of the findings. Architectural and performance effects of different training programs PLOS ONE | https://doi.

These results suggest that the simple method presented here is valid and reliable for computing CMJ force, velocity, power, and F-v profiles in athletes and could be used in practice under field conditions when body mass, push-off distance, and jump height are known.

In sprint kayaking the role that paddling technique plays in optimizing paddle forces and resultant kayak kinematics is still unclear. The aim of this study was to analyze the magnitude and shape of the paddle force-time curve at different stroke rates, and their implications for kayak performance. Ten elite kayak paddlers (5 males and 5 females) were analyzed while performing 2000-m on-water trials, at 4 different paces (60, 80, and 100 strokes per minute, and race pace). The paddle and kayak were instrumented with strain gauges and accelerometers, respectively. For both sexes, the force-time curves were characterized at training pace by having a bell shape and at race pace by a first small peak, followed by a small decrease in force and then followed by a main plateau. The force profile, represented by the mean force/peak force ratio, became more rectangular with increasing stroke rate (F[3,40] = 7.87, P < .01). To obtain a rectangular shape to maximize performance, kayak paddlers should seek a stronger water phase with a rapid increase in force immediately after blade entry, and a quick exit before the force dropping far below the maximum force. This pattern should be sought when training at race pace and in competition.

Compared to SJ, F-v relationships were shifted to the right in CMJ, with higher P max, maximal theoretical force and velocity (+35.8, 20.6 and 13.3%, respectively). As in SJ, CMJ performance depends on Fv IMB, independently from the effect of P max, with the existence of an individual optimal F-v profile (Fv IMB having an even larger influence in CMJ).