After finishing the mile, immediately take your pulse. I would recommend taking a 10 or 15 second pulse at the wrist or neck. Begin your count at zero and count each thump as one beat. Multiply the number of beats by 6 or 4 to get number of beats per minute and record this value. Weight should be in pounds.
Age is in years.
If I can dig up some other tests and equations, I'll be sure to post them.