Wearables & DEXA Scanning

Heart Rate Variability (HRV) measures the variation in time between heartbeats. Higher HRV generally indicates better cardiovascular fitness, recovery, and stress resilience. Tracking HRV helps you understand your body's readiness for training, identify overtraining, and see how lifestyle factors like sleep, alcohol, and stress affect your recovery.

Rings (Oura) are most comfortable for sleep and have multi-day battery life, but limited daytime features. Watches (Apple Watch, Garmin) offer the most features including notifications and GPS, but have shorter battery life and can be uncomfortable during sleep. Straps (WHOOP) balance comfort and accuracy with strong recovery metrics but no display.

DEXA (Dual-Energy X-ray Absorptiometry) uses low-dose X-rays to measure body composition with high precision. It's considered the gold standard for measuring body fat percentage (±1-2% accuracy), lean mass distribution, visceral fat, and bone density. DEXA is more accurate than bioelectrical impedance scales or skinfold calipers.

For most people tracking body composition changes, every 3-6 months is ideal. This allows enough time for meaningful changes in muscle or fat mass. More frequent scanning (monthly) is useful during aggressive body recomposition phases. Annual scans are sufficient for general health monitoring or bone density tracking.

It varies by device. WHOOP requires a subscription ($239-399/year) that includes the device. Oura Ring has an optional $6/month membership for advanced features like Sleep Score optimization. Apple Watch and Garmin have no subscription required - all features are included with the device purchase.

Oura Ring leads with 4-7 days of battery life. Garmin watches range from 7-21 days depending on model and GPS usage. WHOOP lasts about 5 days and can be charged while wearing. Apple Watch requires daily charging with 18-36 hours of battery life depending on usage and model.

No. Wearables track real-time metrics like heart rate, HRV, sleep, and activity but cannot measure blood biomarkers like cholesterol, hormones, or nutrient levels. They complement blood testing - wearables show daily trends while blood tests reveal underlying health markers. Both Oura and WHOOP now offer blood testing services that integrate with their wearable data.

Fitness tracking measures activity output - steps, calories, workouts, distance. Recovery tracking measures your body's readiness using HRV, resting heart rate, sleep quality, and respiratory rate. WHOOP focuses heavily on recovery and strain balance. Oura emphasizes readiness scores. Apple Watch and Garmin do both but with less emphasis on recovery optimization.

Yes, major wearables have peer-reviewed validation studies. Oura and WHOOP have been validated against polysomnography for sleep staging with reasonable accuracy. HRV measurements correlate well with medical-grade ECG devices. However, absolute accuracy varies - focus on your personal trends rather than comparing numbers across devices.

Choose Oura for sleep-focused tracking with a comfortable ring form factor. Choose WHOOP for serious athletes wanting strain/recovery optimization with coaching features. Choose Apple Watch for an all-in-one smartwatch with good health features plus notifications, apps, and cellular. Consider Garmin for multi-sport athletes wanting GPS and long battery life.