My vote would be for yoga, since I teach “yoga for equestrians” classes four times per week. But I know that people love pilates, too. I think it all depends on the instructor you’re working with and having her meet the needs of your level of ability (due to injury or conformation or experience) with the level of your activity (how often do you ride, what type of riding you do, what are the challenges you face).
All my classes start with focus on breath and I stress the importance of breath throughout. I’ve done a whole class on breathing and how to use it to calm yourself while riding (based on my own experiences!). I’ve done classes on “energy” and how to use energy in your practice (and with your horse); I’ve done classes on concentration vs. attention (think hard eyes, soft eyes) and using it in the practice, etc. Of course, the postures are done throughout, but because riding is so much a mental game as well as a physical game, I try to incorporate ideas other than just postures.
I tend to focus on three areas in my classes - hips, abs, shoulders, as these are obviously really important in riding. We work on all three in each class, but sometimes we focus more on one vs. the other (yesterday we spent more time on hip openers, for example). We also work a lot on balance and body awareness and working toward achieving symmetry, as we know how important that is for our horses.
The more I do yoga (and I’ve been practicing for almost 15 years), the more I’m able to access my body in the saddle, and the less my body hurts (shoulder pain from an old injury is gone, back pain is a fraction of what it used to be). Yoga is similar to riding in that there are a lot of pieces of alignment that need to fit together in order to safely and successfully execute a position - just like there are a lot of pieces to proper position in the saddle. I think they complement each other in that way - think of your lessons and how your instructor may say “shorten your reins” or “relax through your shoulders” or “right leg back” or whatever it may be. Yoga postures involve the same type of fine-tuning.
I’ve also found the meditative aspects of yoga helpful in my riding. Slowing the breathing down, sitting quietly, and clearing my mind of stress and clutter really help in potentially stressful riding situations (new horse starting to show, for example). I don’t know that pilates works on meditation and “mindfulness” (above and beyond being present in your practice).
I hope you can find a good instructor no matter what you choose. I have a faithful group of students who are all dressage riders, and they have commented that they’ve gained strength, flexibility, balance, body awareness, pain relief, and a way of dealing with stress while working around their horses.
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