Suunto's top GPS and heart-rate linked T6C isn’t cheap, but it’s the ultimate multisport computer for those serious enough to benefit. This watch straps easily and securely onto most bars if you don’t want it on your wrist. The GPS sensor then drops into your pocket or the supplied arm strap to provide 3D speed/distance data on bike or run.
The Comfort Belt HR strap is reliable and very comfortable, and there’s even a dedicated swim recording heart rate strap for triathletes (£130). Setup is intensive, but intuitive, and you can tailor the three screen options. It shows Training Effect during use and creates a coaching plan based on how your body is reacting to each session.