Get in the zone
60-70 per cent of MHR; very comfortable, easy recovery running.
70-80 per cent; steady running; comfortable enough to hold a conversation; most training is done here.
80-93 per cent; tempo effort or ‘comfortably hard’; you may be able to speak in short, broken sentences.
94-100 per cent; hard effort; interval and 5K pace; conversation is limited to a few words at a time.