For endurance athletes who want precise coaching to perfect their training. Zone Optimizer coaches you to train at the right intensity Sport profiles guarantee swift switch between different sports Improves performance with endurance training programs, downloadable from polarpersonaltrainer.com with the Polar Data Link Gives heart rate even in water with a comfortable hybrid transmitter Race Pace helps you cross the finish line in time Light (46g) & always readyfor use with no need for charging Up to 8-11 months of battery life he Polar RCX5 Multi Sport GPS Running Watch is a Triathletes dream watch. The G5 sensor gives GPS based speed & distance data on the bike & run & it also allows you toanylise your route on line after your training session. This fantastic watch even gives you accurate HRdata in the pool because the strap is able to communicate with the watch under water. The RCX5 uses Polar&0s advanced Zone Optimizer technology to adjust your Heatrate zones according to yourcurrent physiological condition. This will alow you towork at exactly the right intensity to ensure that you get the optimumbenefit from you training session. The watch has a sleek design which not only looks great but isfar less bulky thanmost other watches of this type. It will slip under your wetsuit sleeve withoutany difficulty.