monitor comes in.Speed is often used to regulate threshold sessions, typically at between 10K and 10-mile pace. However, this can be hard to judge, especially when the terrain and/or environmental conditions vary from one session to the next. What’s more

every few minutes as you're running, to get a general idea of your rate throughout the session. You will probably find that, even if you maintain the same pace throughout, your heart rate will rise by 5-10 beats over a period of 30 minutes

often see round figures quoted in general guides, ranging from 70-90 per cent of MHR. Unfortunately, the reason they’re so vague is that – as we’ve found out – we’re all different.In the early days, you’d have needed a physiological lab test to find

session up into sections – mile splits, say – and you can compare the averages, maximums and minimums. If you want, you can even set graphs on top of one another for comparison. This is particularly useful when you’re planning strategy for repetitions

GETTY IMAGESCross-training can be quite an education for an HRM user. You've probably spent time fine-tuning ideal heart rate bands for your various running sessions, to the point where keeping to them is almost second nature. But when you climb