Match-running performance of elite female soccer players: The factors affecting performance and training applications
Due to the unpredictable nature of soccer, a match is open to a variety of different factors that may affect player movement, such as environmental or within match situational factors. When practitioners examine match performances, these factors should be considered when providing feedback to coaches and players, and this data should inform the training prescribed. Therefore, this thesis aimed to answer the question, “what are the effects of environmental and situational factors on player movement in international women’s soccer matches?” The secondary question of this thesis is “what is the training approach utilised to peak for international tournaments where such variables are in play?” A comprehensive systematic review of the literature revealed match-factors might affect movement particularly with respect to situational factors. Meanwhile, altitude and temperature reduced match-running in full match and peak period analyses, highlighting the difficulty of playing in these environments. Altitude, temperature, opposition ranking, match outcome and congested schedules were chosen as match-factors for analysis. The aim of the first study was to examine the effects of match-factors on the match-running of elite female soccer players. The main findings observed small to moderate decreases in all metrics (Effect Size - ES = -0.83 to -0.16) in high temperatures and lower total distance at high altitude (ES = -0.54). Playing lower-ranked teams in a draw resulted in moderately greater high-speed running (ES = 0.89), whilst winning against higher-ranked opponents produced moderately greater total distance and low-speed running (ES = 0.75). The second investigation aimed to examine the effect of match-factors in the Peak match-running of elite female soccer players. Less peak distance (ES -0.85) and high-speed running (ES = -0.27), with less distance, high-speed running and accelerations (ES = -0.44 to -0.37) was observed. Drawing a match, compared to winning or losing, increased total distance and high-speed running (ES = 0.32 to 0.43). The aim of the third study was to examine the match-running of full match, and the effect of early or late substitutions. We found that late substitutes completed a greater rate of total distance, high-speed running, accelerations and PlayerLoad than full match and early substitutes (ES = 0.33 to 1.22). The aim of the fourth investigation was to examine changes in match-running, perceived wellness and neuromuscular fatigue during a period of fixture congestion. Mostly trivial findings in the full match analysis were observed, however, with closer examination lower total distance (ES = -0.69) from the first to last match of tournament in players who competed in all matches was observed. Furthermore, self-reported sleep hours declined (ES = -0.94) from the first to the last match, indicating the need for tracking perceived player wellness throughout successive matches. The aim of the fifth study was to examine the effects of 2250 m of altitude on match-running in elite female youth soccer players. Total distance, low-speed running and PlayerLoad were very likely to almost certainly less at altitude (ES = -2.26 to -0.29). In addition, ratings of perceived exertion and heart rate metrics were very likely to almost certainly increased following a submaximal running test at altitude compared to sea-level. Finally, application of match data to the preparation for international tournaments indicated greater training load during preparation for the 2016 Olympics compared to 2015 World Cup during all training blocks (ES -5.92 to -0.66). Following the taper block, all wellness variables were improved compared to both the training and friendly blocks (ES = 0.59 to 2.55). In addition, a delay of approximately one- to two-days was observed between the exposure to a load and the reporting of a change in perceived wellness reported. In summary, match-running is affected by a variety of factors associated with soccer matches. Practitioners should account for these factors when providing feedback to players and coaches, whilst also utilising this information in preparation for matches. This may be by way of loading or coach guidance to understand the effects of a particular factor in the performance of players. Where possible, the inclusion of perceived ratings of wellness should be included to examine the effects of a training programme or a period of successive matches. These ratings should be collected daily in the morning and examined with respect to training loads, either as a rating of perceived exertion of global positioning metrics. Overall, this thesis provides a thorough understanding of match-running in elite females, whilst providing practical recommendations for the preparation of players for competition.