Interrater reliability of a customized submaximal cycle ergometer test

Purpose Graded exercise testing (GXTs) is used to determine maximum oxygen uptake ((V) over dotO(2max)). Recently, customized submaximal exercise testing (CSET) completed on both treadmill and cycle ergometry were validated. Methods Interrater reliability of the CSET for cycle ergometry was examined. Thirteen participants (age 31 +/- 10.2 y, weight 77.9 +/- 10.5 kg, height 176.2 +/- 9.9 cm, body mass index 25.1 +/- 2.9) completed the 2-stage x 3-min CSET protocol performed by two separate testers. True (V) over dotO(2max) was determined using the highest value derived by a GXT and verification bout. Skeletal muscle oxygen saturation ((S) over dotmO(2)), measured using near-infrared spectrometry on the medial gastrocnemius muscle, and (V) over dotO(2) were monitored during each CSET; whereby, (V) over dotO(2) kinetics were modeled breath-by-breath data for each 3-min stage. Measurement agreement was quantified using intraclass coefficient (ICC), typical error (TE), and coefficient of variation (CV). Results "True" (V) over dotO(2max) (ml.kg(-l).min(-1)) between the GXT (41.3 +/- 10.5) and verification (42.5 +/- 11.5) was established (ICC = 0.98, TE: 0.98, CV 2.1%). Estimated (V) over dotO(2max) by tester 1 (42.5 +/- 9.8) and tester 2 (42.7 +/- 8.9) did not differ from "true" (V) over dotO(2max) (F-2,(36) =0.02, p = 0.98, eta(2) =0.00). The second stage evoked a (V) over dotO(2) slow component of 194 +/- 124 ml.min(-1) that corresponded with a time-dependent decline of (S) over dotmO(2). The mean (S) over dotmO(2) from the two CSET testers were highly correlated (ICC =0.91, TE: 4.1%, CV =8.9%). Conclusions The CSET is a reliable and valid procedure and (S) over dotmO(2 )is a useful tool for corroborating the second stage is in the heavy-intensity domain.