I don't know about spider veins, but it kills my hips when I jog on my treadmill. The really bad part it is, I actually LOVE IT! I never ran more than a mile my whole life, now I can run 4 without stopping, probably more if my hips would allow it. I know that doesn't seem like much to some of the more athletic posters, but to me that's practically a marathon. I basically built up to it by walking for 10 minutes, jogging for 2; walking for 9 minutes, jogging for 3; walking for 8 minutes jogging for 4, etc. until I was running 2 miles, 3 miles, then 4! It took a few months, but it is worth it. Now I am a cardio junkie and can't "get into" my weight workouts anymore. If the IMAX's seem daunting, try the walk/run intervals and you'd be suprised how far you can go. Good luck!
Sally