This does change things quite a bit. For some reason, I was thinking high school age athletes.
Check out some of the info this dude has here and in others on his Youtube page. Lots of solid info to be absorbed:
At that young age, regardless of how serious they take football, they're still young kids and there's only so much intensity they can approach. I haven't seen kids that young that even really knew how to sprint or had very sound running mechanics. Run pretty fast, sure, but full-bore sprints? Not quite, so I probably wouldn't train them that way just yet.
Short-distance change of direction drills (like shorter-distance suicides or incorporating lateral running/sidestep variations) would be more along those lines, in addition to medley circuits that combined some in-game activities with general activities (for example, combining jumping jacks, squat thrusts, bear walks, and running a short pass route to catch an easy lob.)