Phase Angle as an Indicator of Cellular Health and Body Composition in Active Older Adults

Authors

Paxton Castillon, Utah State UniversityFollow
Heather Feeny, Utah State University
Abby Hansen, Utah State University
Alyssa McNutt, Utah State University
Matthew Densley, Utah State University
Elizabeth Cafferty, Utah State University
Ben Taylor, Utah Valley University
Nicolas Clark, Utah Valley University
Andrew Creer, Utah Valley University
Dale Wagner FACSM, Utah State UniversityFollow

Abstract

BACKGROUND: Phase angle (PhA), derived from bioelectrical impedance analysis, reflects cellular health and membrane integrity. It is influenced by muscle mass, hydration, and cell membrane function, making it particularly relevant for assessing physiological status in older adults.

PURPOSE: The purpose of this study was to examine relationships between PhA and body composition variables in active older adults participating in the Huntsman Senior Games.

METHODS: This observational descriptive cross-sectional study included 504 participants (307 women, 197 men; mean age 66.3 ± 7.9 years). Data were collected using the InBody 770 multifrequency body composition analyzer at the Huntsman Senior Games in St. George, Utah. Pearson correlation was used to quantify the relationship of PhA to age and body composition measures.

RESULTS: Men exhibited higher PhA values than women (5.4 ± 0.7 vs. 5.0 ± 0.6, p < .001). PhA was negatively correlated with age (men: r = -.68; women: r = -.57; p < .001). Positive correlations were observed between PhA and intracellular fluid, skeletal muscle mass, and skeletal muscle index (r = .35 to .38), while weaker correlations were noted with fat-free mass (r = .29 to .31). Negative correlations were found with fat mass (r = -.10 to -.26) and visceral fat area (r = -.19 to -.33). The strongest association was a negative correlation between PhA and the extracellular fluid/total body water ratio (r = -.87 to -.90).

CONCLUSION: Phase angle is strongly associated with markers of body composition and cellular integrity in active older adults. These findings suggest that PhA may serve as a valuable indicator of cellular health and muscle quality in aging populations.

Recommended Citation

Castillon, Paxton; Feeny, Heather; Hansen, Abby; McNutt, Alyssa; Densley, Matthew; Cafferty, Elizabeth; Taylor, Ben; Clark, Nicolas; Creer, Andrew; and Wagner, Dale FACSM (2025) "Phase Angle as an Indicator of Cellular Health and Body Composition in Active Older Adults," International Journal of Exercise Science: Conference Proceedings: Vol. 14: Iss. 5, Article 25.
Available at: https://digitalcommons.wku.edu/ijesab/vol14/iss5/25