Squatting: Why People Hold Their Breath, the Valsalva Maneuver, and Safety

Why do people hold their breath when squatting?

People often hold their breath during a squat, particularly with heavier loads, to consciously or unconsciously perform the Valsalva Maneuver, a physiological action that significantly increases intra-abdominal and intra-thoracic pressure, thereby enhancing spinal stability and force production.

Introduction

The squat, a foundational movement in strength training, demands significant core stability and muscular coordination. Observe experienced lifters, and you'll often notice a common, sometimes audible, pattern: a deep inhale followed by a moment of held breath during the most strenuous part of the lift. This isn't merely a habit; it's a deeply ingrained physiological response, often an intentional application of the Valsalva Maneuver, designed to optimize performance and protect the spine under load. Understanding the biomechanical and physiological underpinnings of this phenomenon is crucial for both maximizing strength and ensuring safety.

The Valsalva Maneuver: An In-Depth Look

The act of holding one's breath during a squat is a prime example of the Valsalva Maneuver. Named after the 17th-century physician Antonio Maria Valsalva, this maneuver involves attempting to exhale forcibly while keeping the mouth and nose closed, or in the context of lifting, while the glottis (the part of the larynx consisting of the vocal cords and the slit-like opening between them) is closed.

• What is it? Physiologically, the Valsalva Maneuver is characterized by a forceful exhalation against a closed airway. During a heavy squat, this typically involves taking a deep breath, bracing the abdominal muscles, and then descending into the squat while holding that breath. The breath is usually exhaled only once the lifter has passed the sticking point or completed the concentric (lifting) phase.
• Physiological Mechanism:
  • Increased Intra-Abdominal Pressure (IAP): When you take a deep breath and brace your core, the diaphragm descends, and the abdominal muscles contract, compressing the contents of the abdominal cavity. This creates a rigid "fluid ball" within the torso. This increase in IAP acts like an internal pressure belt, providing anterior support to the lumbar spine.
  • Increased Intra-Thoracic Pressure (ITP): Simultaneously, by holding your breath, the air trapped in your lungs increases pressure within the thoracic cavity. This ITP further stabilizes the upper torso and contributes to the overall rigidity of the trunk.
  • Spinal Stability: The combined effect of elevated IAP and ITP significantly stiffens the entire torso. This creates a more stable "pillar" for the spine, reducing shear forces and compressive loads on the vertebral discs and ligaments. It essentially transforms the flexible, segmented spinal column into a more rigid, unified structure.
• Benefits for Squatting:
  • Increased Spinal Rigidity and Stability: This is the primary benefit. A stable spine is less prone to unwanted movement, which is critical when lifting heavy loads that could otherwise cause injury.
  • Enhanced Force Production: A rigid torso provides a stable base from which the powerful muscles of the hips and legs can generate force more efficiently. Without this stability, energy can be "leaked" through uncontrolled spinal movement, diminishing the force transferred to the barbell.
  • Improved Lifting Mechanics: By promoting a more stable and neutral spinal position, the Valsalva Maneuver helps lifters maintain proper form throughout the movement, especially during the eccentric (lowering) and concentric (lifting) phases of a heavy squat.

The Science Behind Spinal Stability

The concept of spinal stability during heavy lifting is paramount. The spine is a marvel of engineering, but it's also vulnerable to injury under excessive, uncontrolled loads.

• Core Bracing vs. Valsalva: It's important to distinguish between general "core bracing" and the Valsalva Maneuver, though they are often used in conjunction. Core bracing involves consciously tightening the abdominal and lower back muscles to create stiffness around the spine, without necessarily holding the breath. The Valsalva Maneuver adds the element of breath-holding to dramatically amplify the internal pressure, thus providing an even greater degree of spinal support. For maximal loads, the Valsalva Maneuver is a powerful adjunct to good core bracing.
• Neutral Spine Maintenance: The goal of increased spinal stability is to help maintain a neutral spine position. A neutral spine refers to the natural curvature of the spine (slight lordosis in the lumbar and cervical regions, slight kyphosis in the thoracic). Deviations from this neutral position, such as excessive rounding (flexion) or arching (hyperextension) under load, significantly increase the risk of disc herniation or other spinal injuries. The enhanced pressure from the Valsalva Maneuver helps resist these unwanted movements.

When is it Appropriate, and When is it Not?

While highly effective, the Valsalva Maneuver is not without its considerations and potential risks.

• Appropriate Use Cases:
  • Maximal or Near-Maximal Lifts: For squats involving heavy loads (typically 80% of 1-rep max or more), the Valsalva Maneuver is widely considered a safe and effective technique to enhance stability and performance.
  • Experienced Lifters: Individuals with a solid understanding of proper form and body mechanics are better equipped to execute the maneuver safely.
  • Compound Movements: It's particularly beneficial for multi-joint, compound exercises like squats, deadlifts, and overhead presses where spinal integrity is crucial.
• Potential Risks and Considerations:
  • Transient Increase in Blood Pressure: The most significant physiological effect is a sharp, but temporary, increase in blood pressure. This occurs as the increased intra-thoracic pressure compresses the major veins returning blood to the heart, leading to a temporary drop in cardiac output and then a reflex increase in peripheral resistance and blood pressure.
  • Fainting or Dizziness: For some individuals, particularly those unaccustomed to the maneuver or with underlying cardiovascular issues, the drop in cardiac output and subsequent reflex can lead to dizziness or even syncope (fainting).
  • Specific Populations: Individuals with pre-existing conditions such as hypertension, heart disease, glaucoma, or a history of stroke should generally avoid the Valsalva Maneuver or consult with a medical professional before attempting it.
  • Hernias: While it can protect the spine, the increased abdominal pressure could theoretically exacerbate or contribute to certain types of hernias in susceptible individuals.

Proper Breathing Techniques for Squatting

Understanding how to breathe effectively during a squat, whether employing the Valsalva Maneuver or an alternative, is key to both performance and safety.

• Executing the Valsalva Maneuver Safely:
  1. Inhale Deeply: Before descending, take a deep breath, filling your lungs with air. Focus on breathing into your belly, not just your chest, to maximize intra-abdominal pressure.
  2. Brace Your Core: Tense your abdominal muscles as if preparing for a punch. This creates a rigid cylinder around your spine.
  3. Hold Your Breath: Keep your glottis closed and hold your breath throughout the eccentric (lowering) phase and the initial concentric (lifting) phase of the squat.
  4. Exhale Post-Exertion: As you pass the sticking point or complete the lift, slowly and controlledly exhale. Avoid a sudden, forceful "pop" that can disrupt stability.
  5. Re-establish Breath: Take another deep breath and repeat for the next repetition.
• Alternative Breathing Strategies: For lighter loads, warm-up sets, or individuals who should avoid the Valsalva Maneuver, continuous breathing is recommended. This involves:
  • Inhaling on the Descent: Breathe in as you lower into the squat.
  • Exhaling on the Ascent: Breathe out as you push back up to the starting position.
  • This continuous breathing maintains oxygen supply and avoids the pressure fluctuations of the Valsalva, though it provides less intrinsic spinal support.

Conclusion

The practice of holding one's breath during a squat is a sophisticated physiological strategy, most commonly manifesting as the Valsalva Maneuver. Its primary purpose is to dramatically increase intra-abdominal and intra-thoracic pressure, thereby creating a rigid, stable core that protects the spine and enhances the efficiency of force transfer from the legs to the barbell. While highly beneficial for heavy lifting and experienced individuals, it's crucial to understand its mechanics, practice it safely, and be aware of its potential risks, especially for those with certain health conditions. When applied correctly, the Valsalva Maneuver is a powerful tool in a lifter's arsenal, enabling stronger, safer, and more effective squatting.