Primary Investigator (PI) Name
Mitchell Zaplatosch
Department
WCHHS – Exercise Science and Sport Management
Abstract
Purpose: Dual-energy X-ray Absorptiometry (DEXA) and InBody (IB) machines are commonly used in research to measure body composition. We sought to evaluate the agreement of these two devices with a change in hydration status. Methods: Twenty-Three (12 females) (mean ± SD; age, 22.6 ± 2.3yrs; height, 169.1 ± 9.2cm; weight, 80.4 ± 35.03 kg) participants were recruited for a hydration intervention study. Each participant collected their urine over a 24-hr period to assess osmolality (UOSMO) and volume (UVOL), as well as body composition assessments using DEXA and IB before (PRE) and after (POST) the intervention. Body composition variables included Fat Mass (FM), Body Fat percentage (BF%), Lean Body Mass (LBM) and for IB additional measures of total body water (TBW), extracellular water (ECW), and intracellular water (ICW) were collected. Paired t-tests were used to evaluate hydration changes across time. Separate mixed effects models were used to assess the relationship between changes in hydration 294 and the difference between body composition measures between devices and to assess the association between IB body water measurements and 24h urinary hydration variables. Results: UOSMO was lower at POST compared to PRE (MD: -97mOsm/kg [-168, -26], t = -2.80, p = 0.010). UVOL was not significantly different between timepoints (t = 0.677, p = 0.505). Neither change in UOSMO or UVOL were significantly associated with changes in LM, BF, or BF% (all ps > 0.05). Changes in UOSMO and UVOL were not associated with changes in TBW, ICW, or ECW (all ps > 0.05). Conclusions: Improving hydration did not meaningfully impact the agreement between DEXA and IB. IB changes did not reflect improvements in 24h UOSMO, suggesting this device should not be used to indicate a change in hydration status. Significant variability in the change in UOSMO between participants warrants further investigation into this relationship.
Presented at
2026 - The Thirtieth Annual Symposium of Student Scholars
Evaluating the Agreement Between Body Composition Measures with Changes in Hydration Status
2026 - The Thirtieth Annual Symposium of Student Scholars
Purpose: Dual-energy X-ray Absorptiometry (DEXA) and InBody (IB) machines are commonly used in research to measure body composition. We sought to evaluate the agreement of these two devices with a change in hydration status. Methods: Twenty-Three (12 females) (mean ± SD; age, 22.6 ± 2.3yrs; height, 169.1 ± 9.2cm; weight, 80.4 ± 35.03 kg) participants were recruited for a hydration intervention study. Each participant collected their urine over a 24-hr period to assess osmolality (UOSMO) and volume (UVOL), as well as body composition assessments using DEXA and IB before (PRE) and after (POST) the intervention. Body composition variables included Fat Mass (FM), Body Fat percentage (BF%), Lean Body Mass (LBM) and for IB additional measures of total body water (TBW), extracellular water (ECW), and intracellular water (ICW) were collected. Paired t-tests were used to evaluate hydration changes across time. Separate mixed effects models were used to assess the relationship between changes in hydration 294 and the difference between body composition measures between devices and to assess the association between IB body water measurements and 24h urinary hydration variables. Results: UOSMO was lower at POST compared to PRE (MD: -97mOsm/kg [-168, -26], t = -2.80, p = 0.010). UVOL was not significantly different between timepoints (t = 0.677, p = 0.505). Neither change in UOSMO or UVOL were significantly associated with changes in LM, BF, or BF% (all ps > 0.05). Changes in UOSMO and UVOL were not associated with changes in TBW, ICW, or ECW (all ps > 0.05). Conclusions: Improving hydration did not meaningfully impact the agreement between DEXA and IB. IB changes did not reflect improvements in 24h UOSMO, suggesting this device should not be used to indicate a change in hydration status. Significant variability in the change in UOSMO between participants warrants further investigation into this relationship.