Finish key sessions with useful information and recoverable fatigue instead of chasing a training-day trophy.
A workout is practice
Intervals and tempo runs develop specific qualities when effort stays aligned with the session. Starting too fast can change the intended stimulus and turn later repetitions into survival.
Use a controlled first repetition and aim for repeatable form.
Leave something for adaptation
The session is only one part of training; recovery and the following days matter too. Stop or adjust when mechanics deteriorate sharply or the effort no longer matches the purpose.
Save all-out racing for appropriate, planned occasions.
Distinguish effort from danger
Chest pain, fainting, severe unexplained breathlessness or confusion is not normal workout discomfort and needs urgent medical attention.