Hi all, you get fitness points for every drill within a workout and the total accumulated amount for each workout is added and given at the end to give you a workout rating. This means you have to complete the workout for the points to be added to your total.
Obviously the better you are at the individual drills, the higher amount of fitness points your receive and the quicker you will unlock the achievement. However this will still take a bit of time to unlock. I found that finding a few good workouts that you can get 5 star ratings in is the best method to get the maximum amount of fitness points per workout.
As a rough guide I have an average score of 97,000 fitness points for the Mossa Fight Workout (30 mins long) and an average score of 23,000 fitness points for the 10 Minute Solutions: Kick Boxing. Over a period of just over one month I got the achievement from completing a mix of the two workouts a few times a week.