The golden rules of H.I.I.T. training : 2. Don't ignore training and recovery :

👉 1. Adapt the difficulty of the training to your profile

2. Don't ignore training and recovery :
Whatever the duration and intensity of the session, it should begin with a 15-minute warm-up (diaphragmatic breathing, light exercises, self-massages,...) 

and end with about 5 minutes of recovery (stretching, self-massages,...).

👉 3. Increase intensity gradually