I don't know about today's army but we ran and did the PT in combat boots. No tennis shoes to be found. Everything was in boots. Our standard to pass the running part of the PT test was a 6 minute mile in fatigues and boots. Most of us did it faster than that but that was the target. The hog platoon had to run it with a steel pot (metal helmet), every one else could run with their helmet liners only.
I served during the draft and we got some of the most out of shape boys in the country. At least half of the trainees could not finish a mile the first week we had them. Most would drop out and puke their guts out. But even if they dropped out they had to finish the mile before breakfast chow. Walking, crawling, whatever but you had to finish. We ran every morning before chow and after a few weeks no one was dropping out. It was a great way to get them in shape.
What other kinds of exercises were done? For example, was the fitness routine focused mainly on bodyweight/calisthenics or were typical barbell/dumbell work included?