Workload Demands Of Position Players In Major League Baseball

Abstract

PURPOSE: The injury burden within Major League Baseball (MLB) is significant in terms of events, days missed and financial cost. The types of injuries experienced by MLB players is diverse and differs by position; likely reflecting different running, throwing and batting-related workload demands. Understanding in-game demands is critical to athlete preparation, monitoring and management as well as return to play following injury however, little is known about the workload demands of position players in Major League Baseball across each of the key activity-domains. This study seeks to describe the physical demands of position players within Major League Baseball to inform physical preparation, monitoring and return to play. Given the uniquely demanding MLB playing schedule (6.3 games per week), demands across a single game, typical 5-day and worst 5-day periods are presented. METHODS: Total and high-speed running distance (>75% Vmax), high-speed running count, hard accelerations (>3.0 m/s/s), defensive and baserunning minutes, total and hard throws (>80% Vmax), and bat swings were calculated from the Statcast Data provided by MLB to each club. Data were limited to players with 100 games or more in the 2018 championship season. 129 players met the inclusion criteria including: 18 1B, 17 2B, 20 3B, 21 SS, 12 C, 16 CF, 10 LF, 12 RF, and 3 DH. Levene’s test was used to assess for Heteroscedasticity. Between group (position) differences were assessed using ANOVA (Bonferroni adjustment; criterion Alpha p=0.05). RESULTS: Significant positional differences were evident across running and throwing but not bat swing metrics. Outfielders did more total (941.9 ± 135.5 yds per game), and high-speed running (87.3 ± 16.9 yds per game) than other positions. First-basemen did more hard accelerations (33.4 ± 8.7 per game). Middle infielders made more throws (3.5 ± 0.6 per game), and shortstops (0.9 ± 0.3 per game) made more hard throws. Bat swings were similar across positions (7.6 ± 1.0 per game). CONCLUSIONS: This is the first description of workload demands for position players in Major League Baseball. This information can inform pre-season physical preparation, in-season monitoring and management and return to play progressions for injured professional baseball players.