Getty ImagesThe conundrum: push yourself too hard and run yourself into the ground. Don’t push yourself hard enough and never improve. The answer: start listening to your heart, not your head, by using a heart rate monitor (HRM). What does a HRM do?Training

Whatever type of runner you are, you should give serious consideration to investing in a heart rate monitor. From as little as £40 you can add a whole new dimension to your training. Strap on a heart rate monitor and you’ll never run too quickly

When Runner's World readers were asked to list their essential kit last year, heart-rate monitors came out on top. Unfortunately for the female runner, using a heart-rate monitor is usually an uncomfortable experience, requiring 10 minutes before

Heart-rate monitors vary hugely in price and functionality. For less than £20 you can pick up an HRM that simply measures your pulse, while parting with £150+ will give you a monitor that will set training zones for you, tell you how many calories

Gone are the days when runners would rate our efforts based on the colour of their cheeks after a run. Heart-rate monitors are now so easy to use, affordable and accurate that there's no excuse for skipping the science bit in your training. Most

treadmill times will probably be faster. Climb Higher Most runners use less oxygen and have a lower heart rate when training on a treadmill than when they run on the roads, so consider tackling a steeper incline (and even going faster) during your indoor

Training with a heart-rate monitor may no longer be the preserve of the elite, but choosing a model perfectly suited to your needs and budget can still be a minefield of technical jargon and seductive (read expensive) features if you’re uncertain

to store multiple run data for future perusal.Heart-rate monitor Not all entry-level watches come with them, but training within target heart-rate zones is a useful alternative to running at a target speed.Functionality Using your watch should not require a

when running. The heart-rate strap adjusts easily and is perfectly comfortable, while the footpod clips easily to your laces with its presence undetectable once it’s on. In training the watch was easy to use. It stores 100 laps or up to seven hours

to an external TV or DVD player). As well as 20 presets and four heart-rate programmes, you can create presets of your own. There’s also a feature called iFit, which enables you to download training programmes from the internet using an SD card. It comes with a