Activity cycles of National Rugby League and National Youth Competition matches

Examination of ball-in-play periods (i.e. match activity cycles) is a method used to provide insight into the physical demands of team sport competition. However to date, no study has investigated the ball-in-play time of rugby league matches. This study investigated the activity cycles (i.e. ball-in-play periods) of elite National Rugby League (NRL) and National Youth Competition (NYC) matches. Video recordings of 393 NRL matches and 388 NYC matches were coded for activity and recovery cycles. Time when the ball was continuously in play was considered activity, while any stoppages during the match (e.g., for scrums, penalties, line drop-outs, tries, and video referee decisions) were considered recovery. The total time the ball was in play was ~55 minutes and ~50 minutes for NRL and NYC matches, respectively. In comparison to NYC matches, NRL matches had longer average activity cycles (81.2 +/- 16.1s vs. 72.0 +/- 14.7s, effect size = 0.60). The average longest activity cycle was also higher (effect size = 0.48) in NRL (318.3 +/- 65.4s) than NYC (288.9 +/- 57.5s) matches. The longest activity cycle from any match was 667s and 701s for NRL and NYC matches, respectively. NRL matches had a smaller proportion of short duration (91-600s) activity cycles. In conclusion, meaningful differences in activity cycles were observed between NRL and NYC matches, with NRL competition demonstrating longer ball-in-play periods, a smaller proportion of short duration activity cycles, and a larger proportion of longer duration activity cycles. These findings suggest that the ability to perform prolonged high-intensity exercise, coupled with the capacity to recover during brief stoppages in play is a critical requirement of professional rugby league match-play