Bodyweight isometrics like a wall sit or lunge hold can often temporarily make the patellar tendon feel better.
This is why a lot of athletes will incorporate them prior to training.
But bodyweight isn’t enough to build tendon strength.
We need to add LOAD.
Heavy isometrics with a challenging load reaching 70% maximum contraction strength can:
1️⃣ Build tendon strength
2️⃣ Improve maximal force production
3️⃣ Improve rate of force development