Startup Idea: Personal Training Performance Tracking Software

Startup idea to develop a software that enables personal trainers to track and compare their client's workout intensity levels. The software should average their client's last five workout sessions and provide a percentage of their heart rate, allowing trainers to motivate their clients effectively.

I work in the fitness industry as a personal trainer. What we don't know, is how hard someone is working. We do have fitness trackers that display heart rate on a monitor, but what I need is something that shows me how they compare to their last sessions. I need to know if this person is slacking FOR THEM and not just a generality. The software should average their last five workouts and let me know the percentage of their heart rate that they are at so that I can help motivate them more.