Create a field to track time

Create a field to track time

Hey,

Seems like this should be easy but can't get my mind wrapped around it.

I want to create a field that tracks how long my workout took (actually, its how long until I couldn't go anymore, the Max Out Time if any of you are familiar with Insanity Max 30).

I want a time field so that I can eventually do some reporting to see how much I've improved, time-wise, in my workouts.  Yet, I can't seem to figure out how to properly build a field that can track time... or if it's just a number or single line field and I need to build some script to make it work.

Any help? Thanks!