Good Gear: Heart-rate monitors

It's all about timing. We strap on a variety of electronic gizmos designed to help runners reach their targets without missing a beat

The first question to ask yourself is why you want a heart-rate monitor (HRM). According to Tristan Haskins, a personal trainer and owner of www.heartratemonitor.co.uk, "an HRM can tell you exactly what you are doing and make you less prone to injury and fatigue". Next, ask yourself what you want your HRM to do for you. Each HRM has specific functions. The lower end of the Polar range, such as the A5, is useful for those trying to lose weight, while the Timex is a good all-rounder, although it isn't the most intuitive to use. Most serious runners will consider Polar's S-series range; all runners need the lap-timer and stopwatch facilities HRMs offer. HRMs are simple to set up: strap the sensor band under the pecs or bra strap and across the sternum. It transmits the heart's electrical pulses to the wrist receiver, usually by an FM or analogue signal.

Haskins points out a couple of little-known problems with HRMs. "If you are using one close to another runner wearing one, for instance in a marathon, it may confuse the signal. Similarly, they won't always work in a gym due to electrical interference from the machines."

Sean Fishpool of Runners' World magazine says that to use their full potential it is essential to know your maximum heart-rate and your training zones. On more advanced models, if you stray outside these zones the HRM will bleep. Their most valuable function for most runners, though, is as reassurance during a race – information stored from previous races can be compared with performance on the day.

Stockists: www.heartratemonitor.co.uk, 0845 0900 192

Polar A5

The walk-test function gives users a snapshot of how fit they are. Take a short walk and it can measure your cardiovascular level of fitness. It will then calculate your body- mass index.

Price: £74

Polar S610

The top of the range, with a huge memory capacity. It can guide the serious athlete through warm-up, recovery intervals and cool-down. Data can be downloaded on to a PC for further analysis.

Price: £177.50

Timex Ironman

50 Lap

The Timex's digital transmission reduces interference and crosstalk from other electrical equipment. Records 50 lap times with relative heart-rate for each lap.

Price: £85

Reebok Precision

Once the cruise- control function has been set to your most comfortable heart- rate, the Precision will guide you to within a few beats of the target heart-rate.

Price: £129