Valsalva maneuver

The Valsalva maneuver is an attempt to exhale against a closed throat (glottis) while the abdominal and rib cage muscles contract.^{1Schoenfeld and Snarr (eds.), NSCA’s Essentials of Personal Training, 3rd ed., p. 338.} The resulting pressure supports the spine and reduces the work of the lower back muscles during lifts such as the back squat.^{1Schoenfeld and Snarr (eds.), NSCA’s Essentials of Personal Training, 3rd ed., p. 338.} Maximal force is higher with a Valsalva effort than when pushing while breathing in or out.^{2Zatsiorsky, Kraemer and Fry, Science and Practice of Strength Training, 3rd ed., p. 140.}

Chest pressure reduces blood returning to the heart while blood pressure rises sharply; values up to 320/250 mmHg have been measured during barbell squats.^{2Zatsiorsky, Kraemer and Fry, Science and Practice of Strength Training, 3rd ed., p. 140.} The spike can cause dizziness, disorientation and blackouts.^{3Schoenfeld and Snarr (eds.), NSCA’s Essentials of Personal Training, 3rd ed., p. 339.}

In practice

• Reserve it for resistance-trained clients performing structural lifts such as the back squat or deadlift: inhale, hold through the sticking point, then exhale.^{1Schoenfeld and Snarr (eds.), NSCA’s Essentials of Personal Training, 3rd ed., p. 338.}
• Keep the hold brief, about 1 to 2 seconds, even for experienced clients.^{3Schoenfeld and Snarr (eds.), NSCA’s Essentials of Personal Training, 3rd ed., p. 339.}
• Clients with a known or suspected cardiovascular, metabolic or respiratory condition shouldn’t hold their breath during resistance exercise.^{3Schoenfeld and Snarr (eds.), NSCA’s Essentials of Personal Training, 3rd ed., p. 339.}
• Discourage beginners from holding their breath during light, repetitive lifts.^{2Zatsiorsky, Kraemer and Fry, Science and Practice of Strength Training, 3rd ed., p. 140.}

Where sources differ

The NSCA’s strength and conditioning textbook limits the hold to 1 to 2 seconds because blood pressure can quickly reach triple resting levels.^{4Haff and Triplett (eds.), Essentials of Strength Training and Conditioning, 4th ed., p. 369.} The International Personal Trainer Academy describes holding one breath through the working set during heavy, low-rep work, while warning that it becomes dangerous beyond a few reps.^{5International Personal Trainer Academy, Certified Personal Trainer Textbook, p. 285.}