Reliability and validity of the 3-min all-out running test

Abstract Background/Aim Determine critical speed ( CS ) and running distance above CS ( D’ ), as estimated from the 3-min all-out running test (3MT) is reliable and predictive of CS and D’ determined from time trials. Methods Seven males (26 ± 5 years, VO 2max : 56.6 ± 4.1 ml·kg -1 ·min -1 ) completed an incremental treadmill test, three separate time trials (T lim ) of 800, 1600, and 2400m to determine CS and D’ , and two 3MTs to estimate CS and D’ . Results Estimates of trial 1 ( CS =3.90±0.41 m·s -1 , D’ =176±42 m) and trial 2 (CS=3.89 ± 0.48 m·s -1 , D’ = 183±35 m) of the 3MT did not differ. Estimates of CS (ICC=0.95, CV=2.97%) and D’ (ICC=0.93, CV=5.12%) from the 3MT were reliable. The 3MT trials provided valid estimates of CS as determined using regression of the three time trials (ICCs ranged 0.88-0.93, TE ranged 0.13-0.15 m·s -1 , CV ranged 3.32-4.76%). The 3 MT underestimated D’ by∼16%, a difference exceeding the test-retest variability. Conclusions Estimates of CS were valid and reliable; however, assessment of D’ from the 3MT may not estimate anaerobic capacity accurately.