Hi All. Not new to running but have been reading bits and bobs about base training and how base fitness will ultimately benefit during more intense sessions (anaerobic). Will 10 weeks or so on a base training schedule improve my PBs significantly? I'm looking at starting a base training schedule with times runs instead of distance. I've read that base training should be moderately paced. What would be 'moderate? Will a HRM aid base training? If so, what HR %s am I looking at sticking to during the base programme? Any advice would be gratefully received.