R Pokan, P Hofmann, S P von Duvillard, et al. Oral magnesium therapy, exercise heart rate, exercise tolerance, and myocardial function in coronary artery disease patients (Br J Sports Med 2005;40:773–8). This paper should have been published with the following Commentary. We apologise for this error.

This study re-investigates the effect of oral magnesium therapy on exercise heart rate, exercise tolerance, and myocardial function in coronary artery disease patients. It confirms and extends previous results that oral magnesium supplementation improves resting myocardial function and exercise performance in (magnesium deficient) cardiac patients. The relevant new finding is that this also includes a favourable modulation of the upward deflection of heart rate performance during an incremental exercise test, which indicates improved stress dependent left ventricular function.