Nuevas perspectivas para el entrenamiento de la capacidad de aceleraciónEfectividad del trabajo específico sobre las variables mecánicas del sprint

Abstract

Introduction: For years it has been known that for an athlete to win the speed test he had to move his legs very fast in order to increase the stride frequency and thus reach the highest levels of speed during the maximum speed phase. But recently and thanks to several studies, it has been possible to demonstrate the importance of the orientation in the application of force during the supports, being the horizontal force a determinant in the performance. Therefore, several factors have been investigated in order to relate the importance of acceleration in sprint performance, in order to maximize the transfer between training and sport-specific performance. For better sprint acceleration, it has been shown that greater propulsive force is required throughout the acceleration phase. For this reason, the importance of horizontal force development to improve individual athlete performance is highlighted, with an important part being the inclusion of exercises that focus on force production in horizontal orientations (such as heavy sled training), as they can lead to greater speed development. Using the methodology based on the F-v Profile, training can be targeted to impact the horizontal plane, seeing that training performed under a given resisted sprint load condition can lead to phase-specific adaptations in sprinting. Objectives: (I) To determine the optimal drag load to improve early acceleration determinants (F0, RF and Pmax) in elite athletes. (II) To analyze the effects of heavy drag training and its influence on key sprint performance variables during the 3 weeks following its completion. (III) To analyze how sprint mechanical variables vary during an elite athlete's entire season. Methods: (II) Thirteen male and nine female trained sprinters had their 30-m sprint performance and mechanical outputs assessed one week before (PRE), and one (POST, W1), two (W2), three (W3) and four (W4) weeks after a 10-week training block (10 repetitions of 20-m resisted sprints at the load associated to the apex of their velocitypower relationship: i.e. 90±10 % body mass on average (range: 75-112 %). (II) Thirtysix male and nine female trained sprinters had their 30-m sprint performance and mechanical outputs assessed one week before (PRE), and after (POST), after a 10-week training block (10 repetitions of 20-m resisted sprints at the load associated to the apex of their velocity-power relationship: i.e. 90±10 % body mass on average (range: 75-112 %). (III) An international competitive level man was followed up by evaluating his performance during different stretches of the season (PRE-POST indoor and PRE-POST outdoor) by examining his performance using 30 m sprints and 20 m resisted sprints with the load associated with the peak of his speed-power ratio: i.e. 90±10 % of body mass on average (range: 75-112 %). Results: (I) The variables F0 (percentage change of 2.91 ± 10.41), Pmax (percentage change of 4.67 ± 12.31), RFmax (percentage change of 2.06 ± 9.52) and the times in the sprints of 5 (percentage change of -1. 49 ± 4.08), 10 (percent change of -1.59 ± 4.18) and 20 meters (percent change of -3.58 ± 2.08) have small inference. (II) The variables F0 (percent change of 5.41 ± 6. 96), Pmax (percent change of 5.39 ± 5.87), RFmax (percent change of 3.19 ± 3.69), Sfv (percent change of 8.45 ± 12.45), Drf (percent change of - 0.52 ± 7. 78) and times in the 5 (percent change of -2.11 ± 2.38), 10 (percent change of - 1.82 ± 2.22) and 30 meter sprints (percent change of -1.36 ± 3.53) have small inference when compared Pre-Post. In contrast, when comparing Pre-Peak, moderate changes were observed in the variables F0 (percentage change of 9.89 ± 6.06), RFmax (percentage change of 5.46 ± 2.91) and Sfv (percentage change of 13.98 ± 11.94). (III) The most outstanding results are observed when comparing the first season and the last indoor season, with the percentages of change in F0, v0 and Pmax being -1.62, 13.44, 5.31 and 21.03 respectively. On the other hand, when looking at the percentages of loss, in the transition from the 16/17 to the 17/18 season, it is seen that the F0 decreases by 1.22%, the v0 by 0.66% and finally, the Pmax decreases by 1.72%. As for the change from 17/18 to 18/19 season, we see decreases of 0.46%, 0.76% and 1.41% in F0, v0 and Pmax respectively. Conclusions: Individualized sled training protocols for the development of maximum power can be a valid and specific method for athletes and/or sportsmen and women to develop and improve their abilities in the early acceleration phase. For this purpose and taking into account that these methods cause great fatigue in the athlete, this type of protocols should be programmed knowing that the peak performance will not be immediate and that it will be transferred to the following weeks of the extinction of the same