Can you tell me what you suggest if the resting heart rate is 72, calculate this persons target heart rate and vo2 at 60% of maximum?

90- 153: Remember it is just a target heart rate to get to during exercise, and not a number to get fixated to as you can see this is quite a wide range maximum heart rate in 40 year old is 180 . The benefit you get from exercise is not so specific at particular rate so do not worry to much about the rate just keep regular exercise schedule and follow it good luck.