Glad you caught it in time! Eccentric-focused exercises like negative pull-ups can be especially dangerous since almost all exercise-induced muscle trauma occur

Glad you caught it in time! Eccentric-focused exercises like negative pull-ups can be especially dangerous since almost all exercise-induced muscle trauma occurs while a muscle is lengthening under load. The contraction phase doesn't actually induce much trauma. So, if you are allocating most of your available energy to the lengthening phase, you can induce significantly more trauma than if you evenly allocate effort to both phases. After some intensive research several years ago, I concluded that HIIT was the most effective means of reaching and maintaining a high level of fitness. After injuring myself a couple times, I did more research on injury prevention and settled on the following rules, which have kept me injury-free ever since: 1) If I haven't exercised in the last 3 weeks, my first workout consists of merely going through the motions of each exercise with minimal exertion (no heavy breathing). Even this light exercise triggers the Repeated-Bout Effect which will protect skeletal muscles in the next workout. 2) Have two rest days between each workout. Muscles get stronger on rest days, not on workout days. Two rest days (versus one or three) appear to maximize my gains when my workouts are at a high intensity level. 3) Never increase intensity by more than approximately 20% above the last workout. This keeps me safely within the protective margins of the Repeated-Bout Effect.