check out our training-pace calculator for a better indication of how these intensities translate in practice (calculated from a recent race time) or read our ultimate guide to heart-rate training for the most objective way of monitoring your progress

to your race paces, but heart rate is an equally good guide (especially if you're new and you don't know what your race paces are). The glossary suggests target heart rates, and so even the most basic heart rate monitor (from about £40) will be a valuable

be helpful for you to do much of your training with a heart rate monitor in order to familiarise yourself with the pace and heart-rate zones for the five different levels of effort we’ve used in our London Marathon training schedules (easy, slow, steady

, 305 and 405). Your Forerunner will then guide you through each session with target training paces or heart rates to aim for.Decide whether you want to train by heart rate or pace (if in doubt, choose pace).Download the schedule onto your PC desktop

and advances your pulse rate to the 120-150 beats per minute range. The latter two effects get your heart ready to handle the opening moments of the race without undue stress. Jog for about 8-10 minutes, and then don’t stand around for more than about two

it by the percentages in the table (left). Once you have computed your results, you can begin to use the heart rate ranges in training and racing to ensure you’re working at the proper intensity. Repeat this test several times a year to track your lactate threshold

(or the first 10km five minutes slower than your recent 10K race time). If you haven’t raced recently, consider using your heart rate as a guide, aiming for around 65-75 per cent of your working heart rate. You’re restless and full of energy That

heart's stroke volume or your ability to extract oxygen from blood that changes with age, says Sandra Hunter, an exercise scientist at Marquette University in the USA. "It's that your maximum heart rate declines, and no one can change that. It just

. The heart-rate monitor will also be useful on race day. With the crowd cheering and adrenaline pumping there's a big temptation to go off too fast at the start of the race – but keeping an eye on your heart rate should keep you in check. Get some group

pace (see Pace Guide) and use your heart rate guide, these should be fairly accurate. Where possible, try to do some of your running off-road and some of your speed sessions on an even grass surface.The most important session of the training week