The Nike Triax Elite Heart Rate Monitor and Speed/Distance Monitor is one of the most full-featured personal fitness measurement devices available today. It's the top-of-the-line fitness measurement device from Nike, a company who has been expanding into this space over the past couple of years. The Triax Elite is aimed at runners and walkers because it combines a heart rate monitor with a very accurate electronic pedometer. It also comes with data upload capability to PCs or Macs, and excellent fitness journal software.
The Triax Elite is a stopwatch and a heart rate monitor strap that are both water resistant to 50 meters. It supports display of heart rate, current running pace, and pace target information for interval training. This puts it in the same league as other top-of-the-line fitness measurement devices like the Polar S610i and the Timex Bodylink. The Triax Elite's foot sensor is splash resistant but not as waterproof as the other components.
Nike's fitness journal and workout creation software is among the best I've ever seen. For an example of how powerful the software is, watch the Flash demo of creating a workout. This shows you how to build interval training workouts with point-and-click ease. I don't know of any other software included with a fitness gadget that makes building workouts this easy.
Nike's software also lets you tag workouts with sets of attributes. For instance, you can assign attributes to workouts that you do repeatedly. The Polar Precision Software, by comparison, lets you label each workout, but doesn't do anything to help you compare or aggregate similarly-named workouts.
The features that Polar offers in its S-Series heart rate monitors that are missing in the Nike Triax Elite are estimated V02 max and caloric consumption. Accurate caloric consumpution data is valuable to athletes who are carefully monitoring their diets, either for weight loss or performance optimization purposes. V02 max, the measure of maximum oxygen carrying capacity of an athlete's bloodstream, is an important fitness benchmark that is hard to measure accurately without a fitness lab workup. But, Polar's HRMs do an amazingly accurate job of it considering the data that is available from their system.
A lot of people who would use a Nike Triax Elite, however, would not be as interested in caloric consumpution estimates as in the advanced workout planning and reporting features of the Triax Elite software. I think V02 max is very helpful at certain stages of a long-term training program, but, a lot of people find detailed heart rate data far more important, and there is little apparent difference between Polar and Nike in this area
I was really impressed with the Nike Triax Elite. It is a great system for athletes whose training involves running or race walking at a high level. The system produces and analyzes enough data to be helpful to a professional fitness coach, although it would be better if it supported V02 max and physiological testing mechanisms like the UKK Walking Test or overtraining tests. The included fitness journal software is an improvement over the equivalent software from Polar in most areas.
If you are in the market for an advanced fitness measurement device that is designed primarily for running and has excellent interval management support and journal capabilities, the Nike Triax Elite would be an excellent choice.