[pbhjpbhj]

>If intensity training for a minute was all you needed, you could do sprints in the parking lot to train for a 45 minute 10K. Good luck with that. //

That's not a logical conclusion. The intense workout is to achieve/maintain normal fitness not to enable someone to run a good 10k.

If you can achieve moderate fitness with an intense workout then it seems much more likely to me that a person with such fitness will choose sports or other activities instead of remaining sedentary for the rest of the day.