PlayerLoad Variables: Sensitive to Changes in Direction and Not Related to Collision Workloads in Rugby League Match Play.

PURPOSE

To determine (1) how change-of-direction (COD) workloads influence PlayerLoad (PL) variables when controlling total distance covered and (2) relationships among collision workloads and PL variables during rugby league match play.

METHODS

Participants completed 3 protocols (crossover design) consisting of 10 repetitions of a 60-m effort in 15 s. The difference between protocols was the COD demands required to complete 1 repetition: no COD (straight line), 1° × 180° COD, or 3° × 180° COD. During rugby league matches, relationships among collision workloads, triaxial vector-magnitude PlayerLoad (PL), anteroposterior + mediolateral PL (PL), and PL accumulated at locomotor velocities below 2 m·s (ie, PL) were examined using Pearson correlations (r) with coefficients of determination (R).

RESULTS

Comparing 3° × 180° COD to straight-line drills, PL·min (d = 1.50 ± 0.49, large, likelihood = 100%, almost certainly), PL·min (d = 1.38 ± 0.53, large, likelihood = 100%, almost certainly), and PL·min (d = 1.69 ± 0.40, large, likelihood = 100%, almost certainly) were greater. Collisions per minute demonstrated a distinct (ie, R < .50) relationship from PL·min (R = .30, r = .55) and PL·min (R = .37, r = .61). Total distance per minute demonstrated a very large relationship with PL·min (R = .62, r = .79) and PL·min (R = .57, r = .76).

CONCLUSIONS

PL variables demonstrate (1) large increases as COD demands intensify, (2) separate relationships from collision workloads, and (3) moderate to very large relationships with total distance during match play. PL variables should be used with caution to measure collision workloads in team sport.