What Happens in the Body When You Hold Your Breath During Strength Training?

Holding your breath during heavy lifts is common, whether done consciously or not. Many lifters use this strategy to “create stability,” but few understand the physiological processes involved. The technique is often referred to as the Valsalva maneuver and involves increasing pressure inside the abdomen and thorax by holding the breath while bracing the core muscles.

This can be effective, but it simultaneously affects multiple systems in the body.

Increased Pressure and Spinal Stability

When you hold your breath and contract the abdominal wall:

• Intra abdominal pressure rises

• The spine receives increased mechanical support

• Force transfer between upper and lower body improves

This can enhance stability during heavy lifts such as squats and deadlifts. The increased trunk stiffness reduces micro movement in the spine and may improve control during the most demanding phase of the lift.

Effects on Blood Pressure and Circulation

At the same time, significant cardiovascular changes occur:

• Venous return to the heart temporarily decreases

• Blood pressure can rise sharply

• Heart rate and autonomic regulation are affected

In healthy individuals, short controlled use is generally well tolerated. However, in people with cardiovascular disease, uncontrolled hypertension, or elevated cerebrovascular risk, this response may be problematic.

Neurological Regulation

The autonomic nervous system responds rapidly to pressure changes:

• Baroreceptors detect fluctuations in arterial pressure

• Reflex adjustments in heart rate and vascular tone are triggered

• Rapid normalization occurs once breathing resumes

This explains why some individuals feel lightheaded when releasing the breath after a heavy lift.

Is It Dangerous to Hold Your Breath?

For healthy, trained individuals using the technique briefly and deliberately during maximal or near maximal lifts, it is generally considered safe. Risk increases if:

• The breath is held for prolonged periods

• Maximal straining is performed without experience

• Underlying cardiovascular conditions are present

It is also important to distinguish between intentional bracing for a single repetition and unconsciously holding the breath throughout an entire session.

Who Should Be Cautious?

Extra caution is advised for:

• Individuals with high blood pressure

• Patients recovering from cardiac events

• People at risk of aneurysm

• Untrained individuals lifting heavy without supervision

In rehabilitation settings, controlled breathing throughout the movement is often recommended.

Summary

Holding your breath during strength training increases spinal stability by elevating intra abdominal pressure, but it also causes significant cardiovascular changes. When used appropriately by healthy individuals, it can be a useful performance strategy. However, understanding the physiological impact is essential for safe and individualized application.

Sources

• McGill, S. M. (2016). Low Back Disorders (3rd ed.). Human Kinetics.

• Hackett, D. A., Chow, C. M., & Lyttle, A. D. (2013). Blood pressure response to resistance exercise. Journal of Strength and Conditioning Research, 27(10), 2676–2684.

• Heffernan, K. S., Jae, S. Y., & Fernhall, B. (2007). Cardiovascular responses to resistance exercise. Clinical Physiology and Functional Imaging, 27(6), 342–349.

• American College of Sports Medicine. (2021). ACSM’s Guidelines for Exercise Testing and Prescription (11th ed.).