The effect of substitution frequency on the physical and technical outputs of strikers during field hockey match play

We aimed to determine the effects of substitution frequency on physical and technical outputs of strikers during competitive field-hockey. Five matches were played involving the same two teams, during which three different substitution frequency conditions were assessed: three strikers with no substitutions (Sub3), four strikers with a moderate amount of substitutions (Sub4); and five strikers with a high amount of substitutions (Sub5). Physical outputs were measured using GPS and HR monitors and technical outputs (positioning and possession ratings) were determined using video-analysis. There were no significant differences between conditions for total distance covered per position₇₀ (Sub5=8414±125, Sub4=8422±34, Sub3=8282±0m) and high-intensity (>19km. h^-1) running (Sub5=701±46, Sub4=685±28, Sub3=723±0m). There was a tendency for greater substitutions to result in less decrement in total distance and high-intensity running when 1^st and 2^nd halves were compared. Greater substitutions increased total technical outputs compared to less substitutions (Sub5=241±35, Sub4=207±38, Sub3=173±0). In conclusion, while a greater substitution frequency does not increase the physical outputs of strikers, a higher substitution frequency appears to offsets decrements in physical outputs due to fatigue, as well as increase the technical contributions of strikers during competitive play.