Global positioning system and sport-specific testing.

Most physiological testing of athletes is performed in well-controlled situations in the laboratory. Multiple factors that are hard to control for have limited the use of sport-specific field testing. Recently, the technique of the differential global positioning system (dGPS) has been put forward as a way to monitor the position and speed of an athlete during outdoor activities with acceptable precision, thus controlling the two most important factors of performance in endurance athletics, i.e. inclination and speed. A detailed analysis of performance has been shown to be possible in combination with metabolic gas measurements. The combination of accelerometry and dGPS has also been shown to improve physiological field testing. The technique of dGPS could probably also be combined with other bio-measurements (e.g. electromyography and cycling cadence and power) and may enable other studies of exercise physiology in the field, otherwise restricted to the laboratory environment. This technique may also be of use in general exercise physiology where monitoring of patients with, for example, cardiovascular and pulmonary diseases, could be of interest for the future.