Department of Sports and Computing, Sport Faculty, Pablo de Olavide University, Seville, Spain.
CEDIFA, Andalusian Football Federation, Seville, Spain.
J Strength Cond Res. 2021 Apr 1;35(4):1110-1118. doi: 10.1519/JSC.0000000000002902.
Martínez-Cabrera, FI, Núñez-Sánchez, FJ, Losada, J, Otero-Esquina, C, Sánchez, H, and De Hoyo, M. Use of individual relative thresholds to assess acceleration in young soccer players according to initial speed. J Strength Cond Res 35(4): 1110-1118, 2021-The aims of the current study were (a) to analyze the characteristics of acceleration efforts using individual relative thresholds according to the initial speed during official matches in elite young soccer players according to player position and (b) to compare the differences between absolute and relative thresholds in assessing high-intensity acceleration. Player acceleration profiles were assessed using an individual relative threshold based on their acceleration capacity at different initial speeds (standing, 6, 10.8, and 15 km·h-1), and the number of accelerations (>75% of the maximal acceleration) performed during soccer matches was divided into 3 categories attending to the initial speed. (S1 = 0-7 km·h-1; S2 = 7.1-14 km·h-1; and S3 = ≥14.1 km·h-1). Within-group analyses showed that the number of accelerations performed in each category was higher when the effort started from a static or walking position than at moderate- or high-intensity running (S1 > S2 > S3; very likely to almost certain). Between-group analyses revealed substantial differences between some playing positions according to initial speed. In S1 and S3, central defenders had the lowest number of accelerations (likely to almost certain), whereas midfielders had the greatest number of high-intensity accelerations in S1 and S2. There were also substantial differences between the other playing positions (possibly to almost certain). Regarding relative and absolute thresholds (>3 m·s-2), the results showed that absolute threshold overestimated the number of high-intensity accelerations compared with the individual relative threshold in S1 and underestimated the results in S2 and S3 (almost certain). The use of an individual relative threshold to measure acceleration demands allows to distinguish between the numbers of accelerations in function of the initial speed and playing positions. In addition, the absolute acceleration threshold could overestimate or underestimate the acceleration demands in young soccer players as a function of the initial speed. Then, the absolute acceleration thresholds should be taken with caution in the assessment of acceleration activities.
马丁内斯-卡布雷拉、努涅斯-萨恩斯、洛萨达、奥特罗-埃斯基纳、桑切斯、桑切斯和德霍约，M. 根据初始速度，使用个体相对阈值评估年轻足球运动员的加速情况。J 力量与体能研究 35(4)：1110-1118，2021-本研究的目的是(a)根据球员位置，分析精英年轻足球运动员在正式比赛中根据初始速度使用个体相对阈值进行加速努力的特征，以及(b)比较绝对和相对阈值在评估高强度加速方面的差异。使用个体相对阈值根据球员在不同初始速度下的加速能力（站立、6、10.8 和 15 km·h-1）评估球员的加速情况，并且将比赛中进行的超过最大加速度 75%的加速次数分为 3 个类别，根据初始速度进行划分。（S1=0-7 km·h-1；S2=7.1-14 km·h-1；S3=≥14.1 km·h-1）。组内分析表明，当努力从静止或步行位置开始时，每个类别的加速次数高于中高强度跑动（S1>S2>S3；很可能到几乎肯定）。组间分析显示，根据初始速度，一些比赛位置之间存在显著差异。在 S1 和 S3 中，中后卫的加速次数最少（很可能到几乎肯定），而中场球员在 S1 和 S2 中进行了最多的高强度加速。其他比赛位置之间也存在显著差异（可能到几乎肯定）。关于相对和绝对阈值（>3 m·s-2），结果表明，与个体相对阈值相比，绝对阈值高估了 S1 中的高强度加速次数，低估了 S2 和 S3 中的结果（几乎肯定）。使用个体相对阈值来测量加速需求，可以根据初始速度和比赛位置来区分加速次数。此外，绝对加速度阈值可能会高估或低估年轻足球运动员的加速度需求，这取决于初始速度。因此，在评估加速活动时，应谨慎使用绝对加速度阈值。
