Individual variation in physiological training load during a division III soccer season

This study was performed to evaluate the effect of soccer training during a DIII soccer season on the physiological response of training load. Training load was assessed by tracking individual player heart rates during all training sessions and games. Training load was scaled for each player throughout the season and average responses were characterized for individual positions. INTRODUCTION In recent years, many elite athletic programs have shifted towards a more scientific approach in designing and monitoring their training programs. This trend has been slow to spread to athletics at the collegiate level, and even slower to division III programs. This disparity is due, in large part, to insufficient resources. Following the donation of a training monitoring system on behalf of Dr. Tyler Bosch from the University of Minnesota Educational Technology Innovations, the Saint John’s University men’s varsity soccer team became one of the first known DIII athletic programs to engage in daily heart rate monitoring. Training load can be divided into two categories: external or internal. External training load expresses the work an athlete completed, regardless of any individual characteristics (Wallace, 2009). In soccer, this would be the same volume of work physical output performed by each member of the team during a training session. Conversely, internal training load reflects the physiological load imparted on the individual level; so, each member of the team would have a different internal load at the end of a team training session. A combination of both external and internal training load is suggested for the most accurate assessment of an athlete’s level of fatigue. Monitoring heart rate is one of the most commonly used methods of assessing athletes’ training load. (Borresen, 2008). Evaluation, and subsequent modification, of training load is one of the most effective methods of athletic performance improvement (Halson, 2014). Variation in external and internal training load has been related to changes physical fitness performance, and as such, training load quantification has been implemented widely in elite soccer programs (Los Arcos, 2017). By altering variables such as frequency, duration, and intensity, fatigue can be increased or decreased to fit the goals of particular training sessions. This management of fatigue is essential not only for optimizing competition performance and determining if athletes are adapting to training programs, but also for reducing athletes’ proneness to injury and illness (Thorpe, 2017). Periodization refers to the intentional variation of training with the aim to optimize competitive performance. Team periodization strategies have been relatively unexplored, but it is thought that varying the degree of training is more specific to the individual than the team (Gamble, 2006). In soccer, group exercises can have vastly different training demands between individuals due to the different physical components required of each position; a significant difference in work rate has been found between players of different positions in professional soccer (Di Salvo, 2006). Even further, external training loads have the potential to produce different internal loads in each player simply due to individual variation (Jaspers, 2017). These variations (positional and individual) can make it difficult to optimize individual training load prescriptions. Individual variation in physiological training load during a division III soccer season So, within a single team, there can be a large amount of variation in external and internal training load between individuals (Manzi, 2009). This variation increases when a team has a consistent group of 11 starting players, leaving the rest of the team not exposed to the heightened training load of a competitive match (Los Arcos, 2015). Competitive matches have been shown to be the most physically demanding session of a typical in-season week resulting in the greatest training load; this suggests that training load differences between starters and non-starters can be attributed to competitive matches (Kraemer, 2004). Therefore, the aim of this study was to determine the effect of team training on the physiological effect of individual training load over the course of a DIII soccer season. METHODS Participants Twenty (age 18 – 22) DIII soccer players from Saint John’s University agreed to participate in this study. Within this group, there were 8 center midfielders (CM), 2 central attacking players (T), 6 wide attacking players (W), and 4 central defenders (CB). All athletes were members of the men’s varsity soccer team during the 2016 season. The players trained an average of 6 days a week throughout the season. There was an average of 2 training sessions between each competitive match. Training sessions consisted mainly of a warmup exercise, technical-tactical skill development, and small-sided games. Experimental design The players were each assigned a heart rate monitor that was worn on a chest strap during every training session and competitive match. Live heart rate data was recorded every 5 seconds (Polar Team System, Polar Electro Oy, Kempele, Finland) and loaded on a PC Polar Team software. During each training session, the data was segmented and noted with each drill name and type. The same procedure was followed for competitive matches marking the beginning and each of each half. At the end of each recording, the data set was exported and saved as an electronic spreadsheet (Excel, Microsoft Corporation, USA). Data Analysis Statistical analysis was performed using RStudio (RStudio, Inc., Boston, MA). The main test used to determine statistical significance analysis of variance (ANOVA) using a p value of 0.05 for significance. A Tukey’s test was also used in conjunction with the ANOVA. Individual variation in physiological training load during a division III soccer season