Passive stretches
Passive stretches are performed exclusively at the end of a session. Their purpose is to relax the muscles and aid recovery.
Despite what many people think, passive stretching is not recommended during a training session, in fact it is even recommended against, because it increases the risk of torn muscles and other muscular injuries. In the end it could do more harm than good.
Passive stretching is really an activity for stretching at the end of a training session.
How to do passive stretching You need to focus on each muscle for 20 to 30 seconds. You really need to help it relax, to ensure it's only under slight tension, you shouldn't push it too far and make it painful because this reduces effectiveness, both in terms of the stretches and by increasing the risk of muscle injury.
Ideally, you stretch cold muscles and not warm muscles, a new method which has been approved by multiple high-level athletes. You should wait for between an hour and an hour and a half for your muscles to cool down before stretching.