Purpose: To perform an exploratory characterization of repeated sprint sequences (RSS) and repeated acceleration sequences (RAS) in top level soccer referees.
Methods: 7 field and 7 assistant referees were monitored during 2007 America's Soccer Cup with GPS technology. Sprints of >18 km·h(-1) and accelerations of >1.5 m·s(-2) were considered as high intensity activities. RSS and RAS were defined as a minimum of 3 consecutive bouts interspersed with a maximum of 45 s.
Results: Field and assistant referees performed substantially more accelerations than sprints. Neither field nor assistant referees recorded any RSS. In contrast, total distance performing RAS amounted to ∼37% and ∼20% of the total distance covered by accelerations during the entire match for field and assistant referees, respectively. Only field referees exhibited fatigue-related reductions in RAS characteristics between halves.
Conclusion: The results of the present study would appear to support the appropriateness of a repeated acceleration ability (RAA) concept, instead of the repeated sprint ability (RSA) concept, in soccer referees. Further studies should assess RAS in referees and athletes of different team sports for designing better training exercises and physiological testing.
Keywords: Fatigue; Global Positioning System; Intermittent Sports; Performance; Time Motion.