Our Gyno Health

Here’s How We Test Your Body Water Status

Maintaining optimal hydration is crucial for overall health and well-being, particularly during physical activities like exercise and hot yoga. We use an advanced bioimpedance device to measure various physiologic functions, including looking into water status. Total Body Water (TBW) measurements play a significant role in understanding the body’s fluid dynamics and how hydration levels fluctuate with different forms of physical exertion. In this blog post, we will delve into the science of total body water, explore how it changes during exercise and hot yoga, and discuss the importance of hydration before, during, and after these activities.

Total Body Water and Its Measurements:

At Women’s Health Practice we use our SECA body tool to measure your body’s hydration status. Total Body Water (TBW) is the sum of all fluids in the body, including intracellular and extracellular water. Accurate measurement of TBW provides valuable insights into an individual’s hydration status. Common methods for measuring TBW include bioelectrical impedance analysis (BIA), dual-energy X-ray absorptiometry (DXA), and isotope dilution techniques.

Bioelectrical impedance analysis works on the principle that different tissues conduct electrical currents differently due to variations in their water content. The body is considered to be a conductor of electricity, and the resistance and reactance encountered by an electrical current passing through the body can be measured. Phase angle is a parameter derived from the relationship between resistance and reactance.

We also do the sophisticated Phase angle measurement. This is also a bioelectrical impedance analysis (BIA) parameter that provides insights into the composition and health of the body. While phase angle itself doesn’t directly give the total body water (TBW) value, it is correlated with various body compartments, including intracellular and extracellular water, and can be used in conjunction with other BIA measurements to estimate TBW.

Phase angle is influenced by the integrity of cell membranes. Higher phase angles are generally associated with well-hydrated and healthy cells, indicating optimal cell membrane function. Healthy cells have higher water content, and their membranes allow for efficient electrical conduction.

Intracellular and Extracellular Fluids:

TBW is further divided into intracellular water (ICW) and extracellular water (ECW). ICW is the water within the body’s cells, while ECW is the water outside the cells, including blood plasma and interstitial fluid. The balance between these compartments is crucial for maintaining cellular function and overall physiological equilibrium. Since phase angle is correlated with intracellular water (ICW) and extracellular water (ECW). ICW represents water within cells, and ECW includes water outside cells, such as in the blood plasma and interstitial fluid. Higher phase angles often correspond to a higher ratio of ICW to ECW, suggesting better hydration and cell health. Using a combination of measurements is always the best.

Changes in TBW During Exercise and Hot Yoga:

Physical activities, especially those that induce sweating, can lead to changes in TBW. Both exercise and hot yoga cause an increase in sweating, resulting in a loss of fluids from the body. The fluid loss is not only limited to ECW but also affects ICW to some extent. While the reduction in ICW is relatively small, it underscores the importance of replenishing fluids to support cellular function.

Hydration Before Exercise:

Proper hydration before exercise is essential to optimize performance and prevent dehydration. Pre-exercise hydration helps ensure adequate fluid levels in both intracellular and extracellular compartments. Dehydration negatively impacts endurance, strength, and thermoregulation, increasing the risk of heat-related illnesses.

Hydration During Exercise:

During physical activity, especially in the heat, maintaining hydration becomes even more critical. Sweating is the body’s natural cooling mechanism, but excessive fluid loss can lead to dehydration. Regular intake of fluids containing electrolytes helps replenish both intracellular and extracellular fluids, supporting optimal performance and reducing the risk of heat-related issues.

Hydration After Exercise:

Post-exercise hydration is vital for restoring fluid balance and facilitating recovery. Replenishing both ICW and ECW ensures that cells can function optimally, and the body can recover from the stress of physical exertion. Consuming a mix of water and electrolyte-rich beverages can aid in this recovery process.


Understanding total body water measurements and the dynamics of intracellular and extracellular fluids is essential for anyone engaged in regular exercise or activities like hot yoga. Maintaining proper hydration before, during, and after these activities is crucial for optimizing performance, preventing dehydration, and supporting overall well-being. By prioritizing hydration and being mindful of total body water changes, individuals can enhance their fitness journey and promote a healthier, more balanced lifestyle.


Suzanne Trupin, MD, Board Certified Obstetrician and Gynecologist and owner of Women's Health Practice, Hada Cosmetic Medicine, and Hatha Yoga and Fitness

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