I have sciatica in my right side (among other issues

). Impact exercises are definitely out! Swimming, yoga, pilates I can do, but there's definitely positions I can't do (side leg lifts for example). Pilates helps me a lot, improving core strength improves posture and takes pressure off the nerve. I have a yoga for abs and yoga for back health that are really nice, you don't have to be flexible for either one. I really like the arc trainer at my gym, which is like an elliptical but it's back-and-forth like cross country skiing instead of the feet going around like pedals, if that makes sense? It's the only thing that really gets my heart rate going without aggravating my joints at all.