I'm simply curious, but what do you and your horse accomplish within a 15-20 minute ride? Do you walk and trot around? Do bending/yielding exercises? Do you ask your horse to canter or jump? Within 15 minutes, warm up, do all of that, and have enough adequate time to cool off? Because honestly, if you really had your horses well being as a priority, you would know that 15-20 minutes is not nearly enough time for any of that.
You can always warm up on the ground by walking around and trotting in hand. So when you get on, you can begin by walking a few rounds, trotting a few rounds, loping, then you’re ready to do a few jumps because you’ve already had warmed up your horse a lot beforehand.  When I ride I usually either do short walks in the pasture, or in arena work I do walking/trotting combined with work on backing up, flexing, disengaging the hindquarters, and we circle things and weave through whatever is in the arena. Â
There is a horse/hot walker at my barn so I can always attach Destiny to that, but I prefer to cool her down myself by walking her out and in the summer I hose her down if she got sweaty and then I let her roll in the sand. Â She loves it because it cools her down and every horse likes to roll around.
The purpose of a riding warm up is warm your seat up as well as the back of the horse.
The only person to claim that riding causes a lose of circulation is Alexander Nezvorov who self publishes and is not peer reviewed. He is not a proper source. Horses that are ridden properly actually gain muscle over their top line and are less likely to form sway backs.
Disengaging the hind end is incorrect and will cause a sway back. The whole purpose of proper work is to engage the hind end, bring it under the horse, and to lighten the forehand. If you disengage the hind end, your horse will carry itself on the forehand and have a hollow back and develop long term issues over time.















