A self-paced intermittent protocol on a non-motorised treadmill: a reliable alternative to assessing team-sport...

This study assessed the reliability of a 'self-paced' 30-min, team-sport running protocol on a Woodway Curve 3.0 non-motorised treadmill (NMT). Ten male team-sport athletes (20.3 ± 1.2 y, 74.4 ± 9.7 kg, VO2peak 57.1 ± 4.5 ml·kg(-1)·min(-1)) attended five sessions (VO2peak testing + familiarisation; four reliability trials). The 30-min protocol consisted of three identical 10-min activity blocks, with visual and audible commands directing locomotor activity; however, actual speeds were self-selected by participants. Reliability of variables was estimated using typical error ± 90% confidence limits expressed as a percentage [coefficient of variation (CV)] and intraclass correlation coefficient. The smallest worthwhile change (SWC) was calculated as 0.2 × between participant standard deviation. Peak/mean speed and distance variables assessed across the 30-min protocol exhibited a CV < 5%, and < 6% for each 10-min activity block. All power variables exhibited a CV < 7.5%, except walking (CV 8.3-10.1%). The most reliable variables were maximum and mean sprint speed (CV < 2%). All variables produced a CV% greater than the SWC. A self-paced, team-sport running protocol performed on a NMT produces reliable speed/distance and power data. Importantly, a single familiarisation session allowed for adequate test-retest reliability. The self-paced design provides an ecologically-valid alternative to externally-paced team-sport running simulations. Key pointsSelf-paced team-sport running protocols on a curved NMT that closely match the locomotor demands of competition deliver reliable test-retest measures of speed, distance and power.Such protocols may be sensitive to changes in running profile following an intervention that may not be detectable during externally-paced protocols.One familiarisation session is adequate to ensure test-retest reliability.