This is how we've operated for a long time and it works but it takes some tinkering:
Pros:
-Practices are much more efficient. When planning an uptempo practice, you realize just how much time can be wasted. Coaches are forced to modify drills to get kids moving.
-Practices are shorter. We can easily get the kids in and out in an hour and a half. This also makes practice more efficient at you don't lose the kids' attention as easily.
-You can extend practice and cover more football without going overboard. We can push practice to an hour and forty-five minutes-two hours if need be without the conditioning period looming over our heads.
-The kids tend to practice harder; they don't have a conditioning period looming over their heads so they push it in drills.
Cons:
-There are obviously chalk-it, talk-it, walk-it drills that need to be done. Some coaches convey information quickly while others don't. And, there are times when things just need to be slowed down. There's no point in jamming through a fundamental drill fast when half of the kids are doing it wrong.
-There HAS to be punitive action taken when kids aren't pushing themselves. We tell them "You can condition yourselves through drills or you can condition after practice." Figuring out how to work with that can be difficult. The best solution we've come up with is to have a "two warning" rule; if a kid has to be warned about their effort level twice, they're conditioning after practice. We don't condition the whole team as that defeats the entire purpose of running an uptempo practice. But, the sloths will condition after practice.
-Getting coaches on board can be a struggle. Some coaches believe that the only way to get into shape is by "traditional conditioning". Other coaches buy into the up-tempo practice but don't hold the kids that are being lazy accountable. And, there are coaches who have a hard time implementing an up-tempo practice. They're not used to coaching on the fly and getting the kids moving.