Jonathan Hay wrote:
15 min. stretching
5-8 min. rolls (20 mai ukemi, 20 ushiro ukemi, 15 tobu ukemi)
10 min. suwari waza
45 min. technique practice (usually only one or two techniques)
10 min. randori.
I have been thinking that I'd like to abandon the stretching segment (students could warm up on their own before class begins) in favour of practicing striking, centering, and sensitivity exercises. So much to do, so little time...
I follow a similar routine when teaching. Not only does it help me keep on track time-wise while teaching, it also gives a flow to the class that students pick up and start to expect. There is a lot to be said for routine in class. As Jonathan said, I also believe that when you start ad-libbing you will run out of time or forget to show some of the more basic stuff.
One important point about the very first "thing" in the regime is that I feel it should be exactly the same and all teachers should try to adhere to it as close as possible.
I believe that it is this very first part that sets the tone of the class. In our club we do exactly the same exercises every class and everyone (including the students) know the routine. If you take this in the context of classical conditioning (aka...Pavlov's dogs) then it makes sense that by doing the same thing at the beginning of every class you will gain benefit from that class - as you have before.
I'm sure that everyone has gone to a class a bit angry, or upset or frustrated at something that happens during the day, but once you start training that frustration goes away and by the end of class you feel good again. This is because you are doing something that usually makes you feel good...so that becomes the natural result to the class.
By making the first part of the regime the same every time you are quickly reinforcing this "this is how I feel in class" conditioning and are getting people to quickly be ready to train both mentally and physically.
Our club uses warm-ups to do this. I am sure the same set of strikes/kicks/whatever would accomplish the same thing...as long as it is the same in every class.
Just a thought...