It seems like you will be requiring your users to set up and learn a "secret code" for specifying excersizes. In the above example, the user has to learn what each part of the number represents.
Wouldn't it be more user friendly to set up a conditional value list where the exercises are grouped by category?
In such case, you might select "Pushup" in the category field's value list and then the value list for specifying the specific exercize only lists type of pushups. You could use such a category field for grouping your data for reports much like you have thought of doing with the first part of the number. You can also set up a drop down list or a selection portal where entering a few letters filters the list down to just those items that start with (portal or drop down) or contain (portal only) the text entered. With the above 3 exercises you might rename like this so that a "Starts with" scheme is more effective:
Pushups Clap Swiss
You might add a field that is client specific to adjust the quantity and time for the exersize.
Clients type might be...
A) Special Needs (theraputic or special focus)
F) Limited Time for Gym
You could build a workout specific for each client with repetitions and time to complete.
You might want a client to track his progress versus effort and discipline to give him feed back.
PS: you may not want to understake this to begin but thinking it out so you can expand and grow without a major rewrite is easier.