A Principal Component Analysis in futsal according to game halves: A case study of an amateur futsal cup final.

Abstract

Principal Component Analysis (PCA) has not been used to assess the principal component (PC) of players´ external training loads (TL) in futsal. In addition, no previous study has analyzed the PC of players´ external TL depending on the half of the match in futsal. Thus, this study aimed to assess the PC of players´ external TL considering an entire official futsal match distinguishing by halves (1st and 2nd halves). Two teams of twelve amateur futsal players (Spanish 3rd division) participated in the final match of the futsal cup and external TL was quantified using eight antennas ultra-wideband technology. Through PCA statistical analysis, 10 variables formed the 10 PC. Specifically, three PC for the entire match, four for the 1st half, and three for the 2nd half were extracted. Considering the match as a whole, three PC explained the players´ external TL formed by eight variables: distance covered (m/min), distance covered at high speed running (m/min), distance covered at explosive speed (m/min), total accelerations (n/min), total decelerations between 2-1 m/s/s (n/min), distance covered at 24-50 km/h (m/min), total impacts between 8-100g (n/min) and Jumps performed (n/min). The PC variables differed between halves: a) in the 1st half 74.5% was explained by four PC composed of 8 variables in total, and b) in the 2nd half 67.6% was explained by three PC. The results suggest that the use of only one PC could potentially lead to an underestimation of the external TL demands in futsal matches. It seems that a combination of 3-4 PC from a total of 8 to 10 variables are required to explain senior amateur futsal official games. In addition, the match half should be considered to assess the external TL in team sports.