Lost the will to work out? Resenting your tired, old routine? If that sounds like you, the September issue of MF is your guide to rediscovering the fitness spark. Our lead feature is the most obvious tool for doing so: providing 19 expert- and science-proven tips for first, finding motivation and second, forming the healthy habits that mean motivating yourself is actually no longer necessary. Also in this packed issue: how to track calories properly, and 14 exercises to build a bulletproof core.