What Your Lung Capacity Says About Your Health
Most of us don’t think about our breathing until something feels off — but how well your lungs move air in and out says a lot about your overall health and vitality. One of the most important ways to measure lung capacity is through a test called Forced Vital Capacity (FVC).
What Is FVC?
Forced Vital Capacity (FVC) measures the maximum amount of air you can exhale after taking the deepest breath possible.
It’s a key indicator of how well your lungs, muscles, and rib cage are working together to move air efficiently.
During the test, you’ll take a deep breath in and then blow out as hard and fast as you can into a small device called a spirometer. This gives an objective reading of your lung function — and can reveal much more than you’d expect.
Why We Test Lung Capacity
Your lungs are not just for breathing — they play a vital role in oxygenating your body, maintaining energy, and supporting cellular health.
FVC testing helps us:
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Assess respiratory function and detect early changes in lung health
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Identify postural or muscular restrictions that limit breathing efficiency
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Track improvements with rehab, exercise, and your chiropractic/postural care
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Monitor how lifestyle factors (like activity level, smoking, or chronic stress) impact respiratory performance
Even subtle reductions in FVC can signal early issues with posture, core stability, or respiratory muscle strength — all of which are modifiable.
What Does a Low FVC Mean?
A lower-than-normal FVC doesn’t necessarily mean lung disease — but it does tell us that your lungs aren’t expanding or emptying as fully as they could.
Common causes include:
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Poor posture — slouching or rounded shoulders compress the chest and diaphragm, limiting lung expansion
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Weak respiratory or core muscles
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Asthma or airway inflammation
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Chronic stress or shallow breathing patterns
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Age-related changes in chest wall flexibility
Research shows that even mild postural slumping can reduce lung capacity by up to 15–20%, which means less oxygen, more fatigue, and reduced exercise tolerance over time.
What’s a Healthy FVC?
FVC results are interpreted using your age, height, sex, and ethnicity, since these factors influence lung size.
In general, a “normal” FVC is about 80–120% of the predicted value for your demographic.
| Age Range | Male | Female |
| 5 to 12 | 1.5-2.5 L | 1.5-2.5 L |
| 13-17 | 2.5-4.0 L | 2.0-3.0 L |
| 18-39 | 4.5-5.0 L | 3.0-3.5 L |
| 40-59 | 4.0-4.5 L | 2.8-3.2 L |
| 60+ | 3.5-4.0 L | 2.5-3.0 L |
| FVC (% of predicted) | What It Means |
|---|---|
| ≥ 80% | Normal lung function |
| 70–79% | Mild reduction |
| 50–69% | Moderate reduction |
| < 50% | Severe reduction |
How to Improve Your Lung Capacity
The good news? FVC can often improve with simple, consistent habits that strengthen your lungs and posture.
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Practice diaphragmatic breathing: Breathe deeply into your belly and lower rib cage rather than your chest.
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Work on posture awareness: Open your chest, relax your shoulders, and engage your core.
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Add aerobic exercise: Walking, running, biking, and swimming enhance lung efficiency.
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Strengthen your trunk: Exercises for your back, ribs, and core improve breathing mechanics.
- Get adjusted: making sure your spine and rib cage are all moving on a regular basis can enhance your ability to breathe normally.
Even small changes in posture and movement can make a measurable difference in oxygen delivery and energy levels.
The Takeaway
Forced Vital Capacity testing gives a clear picture of how well your lungs — and your posture — are supporting your overall health. It’s quick, non-invasive, and provides meaningful insights into how your body handles one of its most vital functions: breathing.
By tracking FVC over time, we can detect early changes, celebrate progress, and help you breathe — and live — at your fullest capacity.
