re: OT Runners - opinions on GPS watches?

Nobody needs a GPS watch to run, but it is a HUGE benefit in terms of training. There is a difference between exercising and training without question.

It helps you prevent over/under training, when paired with a HRM you can track periods of fatigue and stress and you how react to recovery. In terms of racing it help you implement our race strategy and not let adrenaline bring you out too fast and can also be a tool in gauging distance when races don't have mile markers every mile.

Are there cons, of course. Some people can become slaves to the numbers, but like you I want the data. I've got a power meter on my bike and ride and run with a HRM.

In training, I want to know what my 100, 200, 500 and 1000 yard splits are when I am pushing it and when I am swimming at my recovery pace. I want to be able
know after a long ride what my HR was when I was in the midst of a 20 minute race effort interval. Over time, if training is effective, the same effort should become easier (lower HR) in similar conditions. When I go on my long run, I want to put some 20 minute race pace intervals in there at different times and I want to see how my body reacts to each interval (via HR).

When I pop out of the water on race day I want to know what my swim time was, then see the exact effort I am putting into the pedals as I ride, then know my pace and how my body is reacting to that pace to know how I am really doing.