I do not utilize static stretching during the warm-up phase of the class or training session and have not for many years due to the body of research which indicates that it may negatively impact the performance of the client during the workout and it also seems counterintiutive to attempt static stretches when the body is not warmed up. Warm-ups usually include a less intense version of the specific skills/drills and activities included in that specific workout which prepares the body quite well for the class or training session.
Following myofascial release performed on a foam roller, we do perform static stretches for all major muscle groups of the body during our final cool down, targeting those specifically utilized during the class or training session.
We also encourage our clientele to self-myofascial release on the foam roller prior to their workouts as this has been shown to be benenficial in improving their performance during their workouts.
Static stretches do not increase core body temperature in and of themselves, so they don’t “warm” the body anyway, but having them in the warmup after you’ve done some rhythmic limbering, movement rehearsal, and perhaps some dynamic (not ballistic) stretching would be fine. Static stretches performed before a cardio workout aren’t going to be the problem that they would be prior to a strength or power workout, so no worries on that score. Static stretches done before power/strength exercise have been shown to reduce quadriceps strength by as much as 12%, and to negate the elastic energy created during the stretch-shorten cycle (this cycle is known to potentiate the body’s ability to perform at its best in activities such as vertical jump, etc.).
I too am old school when it comes to warming up and stretching. In aerobic/cardio dance classes the warm up is used to introduce any new choreography that you might be using and to increase blood and oxygen flow to the major muscle groups and joints. I also incorporate dynamic stretching in the beginning and then immediately after the cardio workout. I work with multiple generations and this sytem has served to avoid injury and to help participants understand the benefits of including flexibilty in their workout regime.
Dynamic stretching as a PART of the warm-up process before active type exercise such as cardio classes, athletic events etc. has been shown to help reduce the risk of injury. I always have my clients perform some dynamic stretching before we workout since their sessions will include some dynamic movements.
I hope that this helps.