The Cardiosport GT2 Digital heart rate monitor gives you five different heart rate zones to choose from but three are set automatically once you input your age or max HR – and the chances of you wanting to exercise in the exact band prescribed by the manufacturer are slim.
The fourth zone option is more interesting; once riding at your chosen intensity, you press a button that sets your 'CardioZone' and you're alerted if you go more than 2.5% above or 7.5% below that level. But we just used the manual setting and decided on our own limits which are easy enough to adjust.
Your HR is displayed in both bpm and as a percentage of max, although you're unlikely to want both formats at the same time so we'd have preferred one larger, more easily readable figure.
The valuable 20-lap memory recalls the amount of time you spent in, above and below the selected training zone of your latest session along with your average HR.
The body and strap look a little low rent, though they stood up perfectly fine in testing, and the prominent buttons are easy to hit even with cold, gloved fingers.