Definitions are funny things. I am into "Iron Sports" as a hobby, and among exercise scientists, there are arguments about how many types of strength there are. A typical definition is 4, although some go up to 7.
Give that professional sports scientists have different definitions for strength, it is totally reasonable for a game to provide it's definition.
For those that are interested, the four common definitions are:
- Starting Strength - the ability to recruit as many muscle fibres at once. Bodybuilders exemplify this with their training
- Explosive Strength - the ability to continue to fire muscle fibres to create accelerative force. Sprints and Olympic weightlifters are the prime examples of this
- Limit Strength - the maximum amount of strain muscles can undertake before failing. This is primarily a powerlifters domain
- Muscle endurance - the ability to hold lactic acid and process energy sources efficiently. This is seen in endurance athletes like cyclists, marathon runners, and crossfit practitioners.