Do you get the 'recommended' eight to nine hours a day sitting hunched over staring at a computer screen just inches away from your face? Do you follow that up with a four hour stint in front of the tele after work? That's what I thought.

Unless we're happy to become a nation of obese Quasimodo-a-likes the increasingly sedentary nature of our day to day life makes the need to exercise ever more important.

More and more athletic aids are springing up in our gadgets to reflect this: there's the Nike+ range (including Nike+iPod), mobile phones with pedometer features and various GPS workout trackers for your mobile like the SportsDo application.

As useful as these are, a standalone product is always going to be better. A good quality Heart Rate Monitor is one such product, we've put three examples to test to see who's going for gold and who takes the wooden spoon.

Just a minute sunshine, what does a heart rate monitor actually do?

Put very simply a heart rate monitor monitors the rate at which your heart beats (no kidding Einstein). Knowledge of this rate is helpful within exercise for a number of reasons and training at different percentages of your maximum heart rate has a different physiological effect on the body, for example working at between 70 - 80 % of maximum heart rate is optimal for improvement of the cardiovascular system.

In order to work out these percentages you need to note your resting heart rate, best tested upon waking in the morning, and then work out your maximum heart rate, roughly 220 beats per minute minus your age (this does vary though, both genetically and with athletic ability). Once you have these figures you can pop them into your HR monitor along with weight, height and age and then it'll be able to calculate target HR zones for you to work in as well other details such as total calories burned. The following are generally accepted as the HR zones:

• Energy Efficient Zone 60 - 70% - Basic endurance and aerobic capacity development - moderate jogging, cycling etc.

• Aerobic Zone 70 -80% - Cardiovascular system development - medium paced activities

• Anaerobic Zone 80 -90% - Lactic acid system development - sprints, weight training, intensity work

• Red line Zone 90 - 100% - Fast twitch muscle fibre development - high intensity sprints, weight lifting, short bursts - only very fit/elite athletes can work out in this zone.

A heart rate monitor allows you to make sure you're working with the right level of intensity for the goal you're working toward, for example if you want to build muscle you need to be working out in short bursts (pumping iron baby!) with great intensity, at least 80% of maximal heart rate. To illustrate this consider the physique of a sprinter (short intense training) versus a marathon runner (long, steady moderate paced training) and you can understand the way the heart behaves under different exercise pressures.

All three of the models we tested work with a wristwatch and chest strap setup, the strap wraps around your chest and electrodes transmit the heart beats to the watch for you to track. Although there are several models available without chest straps (watch only) they're generally considered less accurate and somewhat inferior. We just don't do inferior at GC.

Overview: Price: £70 More info: Cardiosport Chronograph: Yes Backlight: Yes Calories expended: Yes Special features: TiZ (time in zone), CardioZone

Cardiosport GT2

Cardiosport has a wide range of models available offering various levels of sophistication, but we chose the GT2 for its combination of features and reasonable price tag of £70. Like all the models on test, the GT2 equips you with a wristwatch and chest strap. The former is a well sized, easy to read at a glance watch but is slightly let down by the questionable red trimming and awkward buttons. The latter, the strap, is fully adjustable and very comfortable, after a minute or so of exercise you'll be barely aware of it.

Traditionally, because HRMs transmit the signal from the chest strap to the watch, there have been issues with 'cross talk' from other near by monitors - and you thought you were just exercising at a superhuman 275 bpm! Cardiosprort has taken steps to avoid this with its low frequency digital transmission system, massively reducing the chances of signal interference.

Setting up the GT2 is straight forward, you enter the following details into the watch: age, your resting or 'ambient' heart rate, weight (pounds or kilos) and your upper and lower training zone limits (erm, and the time date of course). Now the real fun starts! Or the hell, depending on your viewpoint…

The GT2 has some really cool features and better yet, they're really easy to get to grips with. A colour coded monitor at the top of the display clearly indicates the intensity of heart rate and is supported by the percentage shown just beneath. Unlike the other models on test, the GT2 displays both heart rate in bpm and percentage of maximum heart rate. This display is well positioned and easy to read with the slightest of glances, even in poor light thanks to the backlit display.

You can decide on your target heart zone then set up the GT2 to record your TiZ (time in zone), you can preset a target zone and recall it a the press of a button, review peak and average heart rate of a session (useful for interval training) and, using the 100 hour chronograph, review HR for laps and splits. At the end of a training session a quick press of the 'scan' button will show total calories expended, peak HR achieved and average HR. Nicely this'll be saved in the memory for reference until the next time you exercise.

	At a glance

The good:	Easy to use, excellent display, good range of features
The bad:	Design is a little toy-like, buttons can be uncomfortable to press