20 minutes of running around on floor. Ok, and I will admit I like a few laps and to do the chasses and the like. It's a good group building exercise but takes the edges of the gym floor which makes it more difficult for other groups to do passes of line drills. There is some danger in spraining ankles during the curve of the floor.
Gymnastics is all about the anaerobic. If you're anaerobic, you can be aerobic. If you're flabby, fat and out of shape; you will be poor at being anaerobic. Looking to proper nutrition and conditoning and recovery/sleep regimens is what will make those girls from flab to fit. If you want to simply state the nutrition needs to the gymnasts and parents or do it subtly is your prerogative. With females, I'd be very careful about this, especially toward pre-teen and teen years. To often those femmes are protein, calcium, and iron deficient to their preferred eating habits and diet.
The catch 22 about being anaerobic is you have to be aerobic in the first place. Their needs to be a set level of condition before you sprint and go 100%. However, 20 minutes of running around at a moderate pace is not going to get you anywhere.
It is impossible to " sprint " for 20 minutes. If you think it is, you're a fool who doesn't know jack about running sprints or long slow distance. A body's energy system will not run at peak for that long before transitioning into a whole different energy system.
Body fat composition is higher in long slow distance than sprinters. If you can run 3 miles in 20 minutes, you can probably sprint decently as well. If you only manage about 2, you're not running hard enough. Eventually the body becomes more efficient at doing things anyways like LSD.
Set up a huge circuit with a lot of compound movements for 20 minutes. You'll get a lot more bang for your buck practicing chasse's and those basic drills besides handstands, rolls and cartwheels ( I don't go beyond this as a warmup ) early on and you won't have to do them later. It's a warmup, not a Marine PFT.
Work on legs swings, developes, chasses, lunge walks, inchworms, etc. I wouldn't go straight into handstand walks by handstand forward rolls shouldn't tax the risk and will help warm them up early on.
You'd get a lot more out of these girls doing floor sprints with these girls for 20 minutes and be able to keep up that intensity than asking for them to do it. Know what happens when you redline an engine at Top RPM for 20 minutes. Things pop like pistons, rings, seals. In the human body it's called joints, tendon, and muscles.
Running for 20 minutes would be best at the end of your workouts ( like Geoffrey Taucer reccomended ) but girl's coaches always like to do conditioning first. It's easier to program and get them to do it and not skip it because you are getting carried with skills on events. It's easier to work numbers. Easier is for buttercups.
Too often gymnastics is buried in the Bodybuilding split methodology of working out. Good things like muscle rest and recovery come from BB, but this is one of those bad habits. You cannot train skills as efficiently post conditioning. If you think so, you're still a fool. It is useful to work specific conditioning or statics earlier on ( presses, crosses ) than later after 2-3 hours of workout ( also because of mental tiredness ).
I think these coaches are just looking for the next quick fix that is all too common in America when it comes to working out. However, getting conditioned and not being flabby isn't about short term but slow and long term development ( like stretching ).
Ahh, the owner is a marathon runner. Everybody likes to bring their background with them when coaching. However it is not always suitable. Sure, I'd like my girls and boys to Olympic lift but I don't see it happening. Nor do they need to be able to break bamboo poles with their legs and endure kicks, punches, slams in their training. They don't need to be able to swim like dolphins. They don't need to be able to know the gameplay scenerios and react to them of baseball or football or on the fly like hockey, soccer or basketball. Nor do they need to be able to tell me what exact angle is their cast or know how to spell every gymnastics term ( though they should be a virtual gymnastics glossary as I tell them so when I ask for a position, they hear it and show it ).
BTW, if they were truly sprinting, there would be girls getting knocked out of the way as the fasters ones lapped and passed them. During a race, the slow 5 minute milers would get lapped by the 4 minute+ milers. I know this all too well. Doesn't mean I still could dust them in a lap or half lap besides throwing myself over a pole or throwing a big heavy ball farther than them.