Non-starters vs. starters: Comparison of in-season training load relative to match load in professional soccer players

Background: Sports scientists have studied in-season training periodization with elite soccer teams obtaining some calculations such as relative accumulated load. However, to the best of the authors' knowledge, there is scarce literature about training programs related to the loads imposed during matches in non-starter vs. starter players during different in-season periods.Objective: The main aim of the present study was to compare accumulative match and training load rates and the corresponding training/match ratio (TMr) between non-starters and starters players of an Argentine professional soccer team during two in-season periods (regular competition period vs. match congested period). Methods: Ten players were considered starters if they started the match and completed at least 60 min in three consecutive matches while the other 10 were classified as non-starters (most of the matches played as substitute players) over two 8-week periods. The external load of each player during typical practice sessions and official matches was monitored by GPS. Data on total distance (TD), high-intensity load rate (distance covered at speed > 14.9 km/h per minute, HILR) and high-speed load rate (distance covered at speed > 19.9 km/h per minute, HSLR), number of runs during the load rates (#HILR and #HSLR), high-intensity accelerations and decelerations (> 2.5 m/s2, HIA; < -2.5 m/s2, HID) and high metabolic load distance (HMLD) were monitored. An individual TMr was calculated for each external load measure. Results: There were no significant differences in accumulative match and training load rates between non-starters and starters. Regarding TMr, non-starters presented a lower value in HILR (-12.9%, p = .039), #HILR (-7.7%, p = .032), and HMLD (-9.8%, p = .024). Conclusions: The main finding of this study showed that non-starters did not present an improvement or deterioration in physical performance in the main physical metrics analysed, compared to starter players in both periods. In addition, non-starters presented lower values of TMr for high-intensity patterns during the regular period. This could be attributed to the fact that non-starting players have achieved higher performance in various physical metrics, compared to players who were substituted or completed the entire match.