3 Things You Can Learn from a DEXA Scan
A DEXA (Dual-Energy X-ray Absorptiometry) scan is a powerful tool that provides detailed insights into your body composition. While it's more expensive than basic measurements, it offers valuable information that can help guide your health and fitness journey. Here are three key things you can learn from a DEXA scan:
1. Appendicular Lean Mass Index: Balance and Muscle Distribution
One of the most fascinating aspects of a DEXA scan is its ability to measure your Appendicular Lean Mass Index (ALMI)—essentially, the amount of muscle mass in your arms and legs. This measurement tells two important stories:
First, it indicates whether you have appropriate muscle mass for your height and frame. This is particularly important as we age, since maintaining adequate muscle mass is crucial for functionality, metabolism, and overall health.
Second, it reveals any left-right muscle imbalances. Many people are surprised to discover significant differences between their dominant and non-dominant sides. These imbalances might result from:
- Favoring one side during exercise
- Previous injuries
- Occupational movements
- Sports-specific training
Understanding these imbalances allows you to adjust your training program to address any disparities, potentially reducing injury risk and improving overall performance.
2. Bone Density: Understanding Your Skeletal Health Over Time
A DEXA scan provides a detailed snapshot of your bone mineral density (BMD), measuring how many grams of calcium and other minerals are present in a segment of bone. While only medical professionals can make clinical diagnoses, understanding your bone density can be valuable for proactive health management.
Bone density naturally changes throughout life:
- After 30, bone density gradually declines by about 0.5% per year
- Women experience accelerated bone loss during late perimenopause and the first 5 years of menopause, due to decreased estrogen production
- Men typically lose bone mass more gradually, at about 1% per year after age 70
Clinical DEXA scans are typically recommended for:
- Women age 65 and older
- Men age 70 and older
- Post-menopausal women under 65 with risk factors
- People with significant height loss
- People taking medications that affect bone density
- People with certain medical conditions affecting bone health
3. Visceral Fat: The Hidden Risk Factor
While most people focus on subcutaneous fat (the kind you can pinch), visceral fat—the fat surrounding your organs—is actually more concerning from a health perspective. A DEXA scan precisely measures this hidden fat, which is strongly associated with various health risks.
However, you don't always need an expensive DEXA scan to get a rough estimate of visceral fat. A simple waist circumference measurement can serve as a practical alternative. To measure your waist circumference:
- Locate the top of your hip bones and the bottom of your ribs
- Place the measuring tape at the midpoint between these landmarks
- Measure while breathing normally
- Ensure the tape is snug but not compressing your skin
Food And Training Impact Your Visceral Fat.
A DEXA Scan Is Just One Tool
While DEXA scans aren't necessary for everyone, they provide valuable baseline data and can be particularly useful for tracking changes over time. Whether you're an athlete fine-tuning your training, someone interested in improving their body composition, or simply curious about your health status, these three measurements offer actionable insights for your fitness journey.
Remember: While DEXA scans provide valuable information, they should be part of a comprehensive health assessment in consultation with healthcare providers, particularly when there are specific concerns about bone health or significant risk factors.