Discuss why a physically active job does not guarantee better physical fitness.

Having a job that makes you physically active doesnt imply that the sort of action that the job has got is healthy 
Nor the frequency nor the circumstances can always be healthy and this is reason enough
But still furthermore when taking up a job one can be a bit stressed and hence when taking on the physical activity of the job even if it is sort of healthy it may have some sort of counter productive effects due to the mental state of the worker

The talk test measures ease of speaking during exercise;