Reproducibility of anaerobic and pain thresholds in male patients with intermittent claudication

Purpose: Maximal and submaximal parameters assessed during treadmill tests are used to prescribe exercise training and assess exercise-induced adaptations in patients with intermittent claudication (IC). Although reproducibility of maximal parameters is well documented, the reproducibility of submaximal is not clear. The aim of this study was to identify the reproducibility (reliability and agreement) of heart rate (HR) and oxygen uptake (O2) measured at the anaerobic (AT) and the pain (PT) thresholds assessed during a maximal test in patients with IC. Methods: Twenty male patients with IC underwent 2 cardiopulmonary treadmill tests to maximal pain. The HR and O2 at the AT and PT were identified, and differences between repeat tests were compared. Reliability was determined by intraclass coefficient correlation (ICC). Agreement was assessed by coefficient of variation (CV), standard error of measurement (SEM), smallest detectable difference (SDD), and limits of agreement (LOA). Results: The O2 at AT and PT exhibited moderate reliability and moderate/good agreement (ICC = 0.73 and 0.70; CV = 9.6% and 11.1%, respectively). The HR at the AT and PT exhibited high reliability and good agreement (ICC = 0.87 and 0.92; SEM = 3.9 and 3.2 bpm; SDD = 10.8 and 8.8 bpm, respectively). The LOA for O2 at AT and PT were <=20% and for HR <=11 bpm. Conclusions: The O2 and HR measured at the AT and PT were moderately to highly reproducible in male patients with IC. The HR and O2 at AT and PT may be used to establish training intensity and evaluate training effectiveness for these patients in clinical practice and research