PT - JOURNAL ARTICLE AU - F. S. de Man AU - M. L. Handoko AU - H. Groepenhoff AU - A. J. van 't Hul AU - J. Abbink AU - R. J. H. Koppers AU - H. P. Grotjohan AU - J. W. R. Twisk AU - H-J. Bogaard AU - A. Boonstra AU - P. E. Postmus AU - N. Westerhof AU - W. J. van der Laarse AU - A. Vonk-Noordegraaf TI - Effects of exercise training in patients with idiopathic pulmonary arterial hypertension AID - 10.1183/09031936.00027909 DP - 2009 Sep 01 TA - European Respiratory Journal PG - 669--675 VI - 34 IP - 3 4099 - http://erj.ersjournals.com/content/34/3/669.short 4100 - http://erj.ersjournals.com/content/34/3/669.full SO - Eur Respir J2009 Sep 01; 34 AB - We determined the physiological effects of exercise training on exercise capacity and quadriceps muscle function in patients with idiopathic pulmonary arterial hypertension (iPAH). In total, 19 clinically stable iPAH patients (New York Heart Association II-III) underwent a supervised exercise training programme for the duration of 12 weeks. Maximal capacity, endurance capacity and quadriceps function were assessed at baseline and after 12 weeks. In 12 patients, serial quadriceps muscle biopsies were obtained. 6-min walk distance and peak exercise capacity did not change after training. However, endurance capacity improved significantly after training, demonstrated by a shift of the anaerobic threshold to a higher workload (from 32±5 to 46±6 W; p = 0.003) together with an increase in exercise endurance time (p<0.001). Moreover, exercise training increased quadriceps strength by 13% (p = 0.005) and quadriceps endurance by 34% (p = 0.001). Training enhanced aerobic capacity of the quadriceps, by increasing capillarisation (1.36±0.10 to 1.78±0.13 capillaries per muscle fibre; p<0.001) and oxidative enzyme activity, especially of the type-I (slow) muscle fibres. No changes were found in cross-sectional area and fibre type distribution. Exercise training in iPAH improves exercise endurance and quadriceps muscle function, which is also reflected by structural changes of the quadriceps.