Here are the answers to your questions:
1. The 4 Principles of Training are Specificity, Overload, Progression, and Reversibility.
2. F.I.T.T stands for Frequency, Intensity, Time, and Type - the four ways to achieve Overload in a training program.
3. If you progressed an exercise program too quickly, it could result in injury to muscles and joints. The body needs time to gradually adapt to increased demands through progressive overload.