Criterion-related validity and test–retest reliability of the 20 m Square Shuttle Test

SummaryWe assessed validity and reliability of the new 20 m square shuttle run test (SST) for predicting maximal oxygen uptake (V˙O2max) and compared it with its predecessor, the 20 m Multistage Shuttle Run Test (MST). In a repeated-measures randomised-block design, 74 healthy adult males performed the SST, the MST and a treadmill test (TT). To assess reliability, 40 of the total 74 volunteers were randomly-selected to perform the SST and MST twice. Unlike the SST (p > 0.05), mean predicted V˙O2max(V˙predO2max) from the MST was significantly increased from that measured during the TT (p < 0.05). The V˙predO2max from SST and MST correlated with TT V˙O2max at r = 0.95 (p < 0.001) and r = 0.63 (p < 0.001), respectively. Prediction error of SST was −0.3 ± 3.3 ml kg−1 min−1 with a coefficient of variation of ±3.5%, while the equivalent values for MST were 4.2 ± 7.3 ml kg−1 min−1 and ±7.4%. Mean test–retest V˙predO2max did not differ for both SST and MST (p > 0.05), while the corresponding test–retest correlation coefficients were r = 0.85 (p < 0.001) and r = 0.72 (p < 0.001). Reliability errors in 95% limits of agreement were 0.3 ± 4.8 and 0.6 ± 6.8 ml kg−1 min−1 while coefficients of variation were ±5.2% and ±6.8% for the SST and MST, respectively. It is concluded that SST is a more valid proxy than MST for predicting laboratory V˙O2max based on the current procedures, while both tests are sufficiently reliable in healthy male adults.