To the Editor We read with interest the recent multicentre UK study by Sandercock et al1 quantifying prescribed exercise volume and changes in cardiorespiratory fitness (CRF) involving 950 patients across four UK outpatient cardiac rehabilitation (CR) centres. Although CRF improvements varied, the overall improvement in CRF (0.52 METS) was only one-third the mean estimate reported in their earlier meta-analysis (1.55 METs).2 The authors indicated that if representative of UK services, these low training volumes and small increases in CRF may partially explain the reported inefficacy of UK CR to reduce patient mortality and morbidity, as outlined by the RAMIT group.3 We agree with the assertion that lower …