Source comparison
Common Preparation Errors That Invalidate DEXA Comparisons
TB-500 research DEXA scan notes are only meaningful when scan conditions are standardised. The most common error: hydration variability between scans. DEXA measures lean mass by detecting water content in tissue. A 2% shift in total body water (roughly 1.5 lit
This comparison does not assign a generated winner or score.
- TB-500 research DEXA scan notes are only meaningful when scan conditions are standardised. The most common error: hydration variability between scans. DEXA measures lean mass by detecting water content in tissue. A 2% shift in total body water (roughly 1.5 litres in a 75kg subject) can produce a false 1kg lean mass change on the scan readout. Research protocols require subjects to fast for 4 hours and consume exactly 500ml water 90 minutes before each scan to minimise hydration-driven noise.
- Glycogen status is the second variable that distorts scan-to-scan comparisons. Muscle glycogen binds 3–4 grams of water per gram of carbohydrate stored. A subject who carb-loads the day before scan 1 and restricts carbohydrates before scan 2 will show a false 0.8–1.2kg lean mass loss purely from glycogen depletion. Not actual muscle tissue change. TB-500 research protocols standardise carbohydrate intake at 3–4g per kg body weight for the 48 hours preceding each DEXA scan.
- The third factor: scan positioning. DEXA software calculates regional body composition based on anatomical landmarks. The space between the ribs and pelvis defines 'trunk,' the femoral head defines the leg boundary. If a subject lies 2cm higher or lower on the scan bed between sessions, the software recalculates regional boundaries and produces false lean mass shifts between body segments. Research-grade DEXA facilities use laser positioning guides to reproduce positioning within 5mm across all scans.
- Our team's experience with peptide research participants: the single most frequent error is weighing in at different times of day. A DEXA scan performed at 8 AM (post-overnight fast) versus 6 PM (post-meals, post-training) can show a 1.5kg total mass difference from food weight, water retention, and glycogen flux. None of which represents actual tissue change.