1. When the muscles contract, hold your breath instantly and exhale quickly, and when the muscles stretch, inhale slowly. Generally, this breathing method is used when the load is heavy, the action is carried out in supine position, or the shoulder strap and chest and abdomen must be fixed. In chest exercises, deep inhalation is allowed to achieve the requirement of holding out the chest as much as possible, but the time of holding your breath must be short and exhale.

2. Breathe in quickly when muscles contract, and exhale slowly when muscles stretch. This way of breathing is contrary to the above formula. It is fast and powerful when inhaling and slow and long when exhaling. Generally used for light load and concession exercises.