Eur J Appl Physiol (2007) 101:547–554 DOI 10.1007/s00421-007-0530-8 123 ORIGINAL ARTICLE Low agreement of ventilatory threshold between training modes in cardiac patients Dominique Hansen · Paul Dendale · Jan Berger · Romain Meeusen Accepted: 6 July 2007 / Published online: 1 August 2007  Springer-Verlag 2007 Abstract In cardiac rehabilitation, diVerent endurance exercises such as walking and cycling are often performed. The training intensity for these modes is determined from a single treadmill or bicycle test by ventilatory threshold (VT). In this study, diVerences of VT between walking and cycling and agreement of VT between training modes were assessed in cardiac patients. A total of 46 cardiac rehabilita- tion patients (mean age 59.5 § 8.4 years, 45 males) (31 untrained and 15 trained) completed a maximal exercise test on bicycle and treadmill, with breath-by-breath analysis of oxygen uptake (VO 2 ), carbon dioxide production and expiratory volume. VT was determined by V-slope method. Correlations of VT and VO 2peak were calculated between exercise modes. Bland–Altman plots were made for deter- mining VT agreement between modes. VT was signiW- cantly diVerent between walking and cycling in trained patients (P < 0.05), but not in untrained patients (P > 0.05). When untrained and trained patients were compared, VT correlation was lower (r = 0.50) in the former group, as compared to the latter group (r = 0.78). Also, Bland–Alt- man plots showed smaller limits of agreement for VT in trained (2 SD ¡1.6 to 7.8 ml/min/kg), as compared to untrained patients (2 SD ¡7.0 to 9.6 ml/min/kg). In trained patients, VT correlates well between training methods, but is highly exercise mode speciWc. In untrained patients, VT is not exercise mode speciWc, but the VT has a low correla- tion between training modes. This study shows that VT should be assessed by the appropriate exercise model for determining exercise intensity in cardiac rehabilitation. Keywords Ventilatory threshold · Walking · Cycling · Cardiac rehabilitation Introduction Two decades ago, a new method for non-invasive detection of the anaerobic threshold, referred to as ventilatory thresh- old (VT) (Beaver et al. 1986), was introduced. This appli- cation, based on increasing carbon dioxide production relative to oxygen uptake during incremental workload, might be relevant to many cardiac rehabilitation pro- grammes. Studies have shown that VT correlates well with lactic acid accumulation threshold and therefore reXects the highest working intensity before plasma lactate accumula- tion occurs (Dickstein et al. 1990). In addition, as many cardiac patients are under beta-blocker treatment, which alters the heart rate-oxygen uptake relationship, VT might provide a valid alternative for training intensity determina- tion (Wonisch et al. 2003). Because of the relevance of VT application in cardiac rehabilitation programmes (Wonisch et al. 2003), much eVort has been put into optimising its detection within one exercise mode. However, despite a good correlation between VT and lactic acid accumulation threshold, recent reports showed contradictory results on the reproducibility of VT within one exercise mode (Bosquet et al. 2002; Cohen-Solal et al. 1991; Shimizu et al. 1991). Various fac- tors might aVect the occurrence of VT and therefore com- D. Hansen · P. Dendale · J. Berger Rehabilitation and Health Centre, Virga Jesse Hospital, Hasselt, Belgium D. Hansen · R. Meeusen (&) Faculty LK, Department of Human Physiology and Sportsmedicine, Vrije Universiteit Brussel (VUB), Pleinlaan 2, 1050 Brussels, Belgium e-mail: rmeeusen@vub.ac.be