Has anyone ever torn their gastroc (calf muscle)?  I have had this injury before but was devastated when I did it in the other leg while running sprints.  I have been off for two weeks (one week to go before I can start running again) but I was planning on running in my first half-marathon in 4 weeks!   I'm wondering if I should still try to jog/walk the half, so that I can get some experience and then sign up and train in earnest for another race.