Your best bet is to listen to your pain. Pain is an indicator of worse things to come. If it hurts alot, then ease off the paddling for a week or two. When it feels better, then work on strengthening the tendons with light excersize. Be aware of your condition. I know it sounds stupid, but alot of people will continue to do activities that result in chronic pain. That's when you'll end up under the knife. Try getting some advice from your school's Med center or Med school professors.