Comparison of training and match load between metabolic and running speed metrics of professional Spanish soccer players by playing position.

The aims of this study were to compare the training and match load of professional soccer players according to the playing position, and analyse the relationship between the metabolic and running speed metrics. Thirty professional male soccer players belonging to a Spanish First Division team were analysed using global positioning system devices (GPEXE Pro 18.18 Hz) during training and competition (n = 36 training weeks and n = 41 matches). The results showed significant differences between positions on match day; central midfielders covered higher total distance and low- and medium-speed running distance (moderate to large effect size) than central defenders, external defenders and forwards; forwards performed more metabolic power events than central defenders, central midfielders and wide midfielders; and central defenders showed the lowest very-high-speed running. Different patterns were observed in training. Furthermore, the equivalent-distance index showed a strong correlation with accelerations and decelerations events. The main findings were that the physical responses found in training did not correspond with match demands by position; both metabolic and traditional approaches should be used together for load monitoring in professional soccer players; and finally, metabolic power events and the equivalent-distance index seem to be variables that help to differentiate more clearly the characteristics of the player, taking into account their playing position.

A New Approach for Training-load Quantification in Elite-level Soccer: Contextual Factors.

The aims of this study were to analyse the physical responses of professional soccer players during training considering the contextual factors of match location, season period, and quality of the opposition; and to establish prediction models of physical responses during training sessions. Training data was obtained from 30 professional soccer players from Spanish La Liga using global positioning technology (N=1365 performances). A decreased workload was showed during training weeks prior to home matches, showing large effects in power events, equivalent distance, total distance, walk distance and low-speed running distance. Also, the quality of the opposition also affected the training workload (p<0.05). All regression-models showed moderate effects, with an adjusted R2 of 0.37 for metabolic-work, 0.34 for total distance covered, 0.25 for high-speed running distance (18-21 km·h-1), 0.29 for very high-speed running distance (21-24 km·h-1), 0.22 for sprint running distance (>24 km·h-1) and 0.34 for equivalent distance. The main finding of this study was the great association of match location, season period and quality of opposition on the workload performed by players in the training week before the match; and the development of workload prediction-models considering these contextual factors, thus proposing a new and innovative approach to quantify the workload in soccer.

How does the mid-season coach change affect physical performance on top soccer players?

The aim of this study was to analyze the locomotion and metabolic responses of professional players in the top three competitive standards of Spanish soccer (First, Second and Second 'B' division) during the four weeks before and after dismissal the coach. Training and match load data were analyzed separately (n = 1189 events) by coach (dismissed coach and the new coach) and Wilcoxon-test was performed to compare data between coaches. In training, players covered longer distance in all speed ranges >14 km•h - 1 with the coach dismissed; medium (14-18 km•h - 1), high (18-21 km•h - 1), very-high (21-24 km•h - 1) and sprint running distance (>24 km•h - 1) (d = 0.53, 0.46, 0.58 and 0.54; respectively) on first division; and equivalent distance index and accelerations events (d = 0.63 and 0.50; respectively) on second division. Lower differences were found in matches, in which the dismissed coach showed higher equivalent distance index, accelerations and decelerations events (d = 0.69, 0.68 and 0.61; respectively) compared to the new coach in the second division. Therefore, the players covered longer high-intensity distance with the dismissed coach than the new coach in training, whilst a similar performance was found in the competition. These results suggest that the coach turnover at mid-season did no increase the players' physical performance either in training or in competition.

The Effect of Weekly Training Load across a Competitive Microcycle on Contextual Variables in Professional Soccer.

Analysis of the key performance variables in soccer is one of the most continuous and attractive research topics. Using global positioning devices (GPS), the primary aim of this study was to highlight the physiological response of a professional soccer team across competitive microcycles in-season according to the most influential contextual performance variables. Determining the training load (TL), a work ratio was established between all recorded data within the training sessions and the competitive profile (CP). Each microcycle was classified in accordance with the contextual variables: opponent level (high, medium, low), match location (home and away) and score (win, draw, lose). Results revealed that the team were significantly more successful (games won) in competitive games against high-level opponents and when played at home. Cumulative microcycle/weekly training load (WTL) was significantly lower when the team won. In addition to the opponent level and the match location, WTL could condition the athlete's performance in the competition. Competitive performance responses are the main source of information for the planning of training programs. The results of this study could be used as a reference to structure TL and WTL according to contextual variables in the competition. This study, which is the first of its kind, revealed that WTL effects the performance of the players in the competition.