The Ironman range has stood the test of time and this unit provides the customary sound performance.
You can input three different heart rate (HR) zones based on beats per minute (bpm) or a percentage of your max and you get another five that are laid down automatically; you can set the watch to beep and/or flash to alert you if your intensity wanders from whichever one you choose.
The stopwatch displays your lap time and overall time simultaneously which means less button pushing, while the interval training mode is an excellent feature that allows you to input five different workouts based on time or HR.
Unusually, within each interval session, you can plan a warm-up, four different work/rest periods that are repeatable up to 99 times if you're feeling really energetic, and also a useful cool-down.
The details of your session are all recorded – most useful is the amount of time spent in each HR zone – but you need to remember to take down your vital statistics because they'll be erased the next time you start the stopwatch.
There are no bike-specific features, although you can add speed and distance measurements with a GPS-3D sensor for £84.99 extra.