An interesting article published (The Star In.Tech June 16th, 2005 page 2) highlighted the use of PDA in a Fitness Centre (Fitness First).
The instructors will log the data into the gym's information system to keep track of an individual member's progress. They can also track exercise perfromances with the PDAs.
If Fitness First members visit an out-of-town centre, they can also update their records and from there, their progress can be monitored online. Personalised training data and programmes can be developed and designed for individual member.