Heavy slow resistance vs eccentrics, what I actually tell people

This comes up in half the threads here, so let me lay it out once. Eccentrics and Heavy Slow Resistance (HSR) both work. The data does not crown a clear winner, but here is what actually dictates success in the real world: 1. Adherence is everything. Running an HSR protocol 3 days a week for 6 months beats a twice-daily eccentric routine you abandon after 3 weeks. 2. Match the site and range. Insertional Achilles needs range limits like flat-ground calf raises rather than deep deficit drops. Patellar tendons thrive on heavy slow leg presses and hack squats. Upper body tendons take far less absolute load than people think. 3. Progress the weight. The biggest mistake in self-directed PT is staying at the same safe load from week 2 to week 12. If you do not titrate the weight up, you are just maintaining, not rebuilding tissue. 4. Manage the flare-ups. Mild soreness during the work that settles within 24 hours is fine. Sharp pain or worse baseline stiffness the next morning means you overshot your load. 5. Respect the timeline. 12 weeks is your first real evaluation mark, and 6 months is a standard cycle for full tendon remodeling. Mechanical loading is the primary driver here. Pinning BPC-157, TB-500, or GH is an adjunct to the physical work, not a shortcut around heavy reps. Load the tissue first.