Bioimpedance-derived phase angle as an additional predictor of treadmill spiroergometric performance in young elite athletes

Tamas Dobronyi; Bettina Beres; Peter Bakonyi; Gergo Simon; Fanny Zselyke Ratz-Sulyok; Csilla Jang-Kapuy; Annamaria Zsakai; Tamas Szabo

doi:10.20330/AnthropKozl.2026.67s.52

Tamas Dobronyi Hungarian Handball Federation, Directorate of Sport Science and Diagnostics, Budapest, Hungary
Bettina Beres Hungarian Handball Federation, Directorate of Sport Science and Diagnostics, Budapest, Hungary
Peter Bakonyi Hungarian Handball Federation, Directorate of Sport Science and Diagnostics, Budapest, Hungary
Gergo Simon Hungarian Handball Federation, Directorate of Sport Science and Diagnostics, Budapest, Hungary
Fanny Zselyke Ratz-Sulyok Hungarian Handball Federation, Directorate of Sport Science and Diagnostics, Budapest, Hungary; Eotvos Lorand University, Faculty of Science, Department of Anthropology, Budapest, Hungary
Csilla Jang-Kapuy Hungarian Handball Federation, Directorate of Sport Science and Diagnostics, Budapest, Hungary; Eotvos Lorand University, Faculty of Science, Department of Anthropology, Budapest, Hungary; Eotvos Lorand University, Faculty of Science, Doctoral School of Biology, Budapest, Hungary
Annamaria Zsakai Hungarian Handball Federation, Directorate of Sport Science and Diagnostics, Budapest, Hungary; Eotvos Lorand University, Faculty of Science, Department of Anthropology, Budapest, Hungary
Tamas Szabo Hungarian Handball Federation, Directorate of Sport Science and Diagnostics, Budapest, Hungary; Eotvos Lorand University, Faculty of Science, Department of Anthropology, Budapest, Hungary; Eotvos Lorand University, Faculty of Science, Doctoral School of Biology, Budapest, Hungary

DOI: https://doi.org/10.20330/AnthropKozl.2026.67s.52

Keywords: Bioimpedance-derived phase angle, Spiroergometry, DEXA, Sport diagnostics, Youth handball

Abstract

Background: Understanding the relationship between athletes’ structural characteristics and functional performance requires assessment of both body composition and internal physiological status. Bioimpedance analysis provides parameters related to tissue bioelectrical properties, including phase angle. Evidence on the relevance of phase angle in spiroergometric assessments of young elite athletes remains limited.

Objective: This ongoing study examines whether bioimpedance-derived phase angle provides additional explanatory value for time to exhaustion and allometrically scaled VO₂ peak beyond age, body height, and DEXA-derived skeletal muscle proportion.

Subjects and methods: Preliminary analyses included 94 female and 130 male elite handball players aged 13–25 years. Female recruitment is ongoing, while male data collection is complete. Participants completed a stepwise incremental treadmill protocol to maximal voluntary exhaustion. VO₂ peak was calculated from a 30-second moving average of breath-by-breath data and allometrically scaled to body mass. Bioimpedance was assessed using an InBody 770 device. Phase angle was the main explanatory bioimpedance variable; device-generated resistance and reactance Z-scores were retained for potential vector-based bioimpedance interpretation. Skeletal muscle proportion was assessed by DXA. Sex-stratified multiple regression models examined the explanatory value of skeletal muscle proportion and phase angle beyond age and body height.

Results: Preliminary sex-stratified regression analyses suggested that DEXA-derived skeletal muscle proportion accounted for additional variance in time to exhaustion and allometrically scaled VO₂ peak compared with models containing age and body height only. Phase angle showed a small but significant additional contribution, mainly for time to exhaustion. The overall pattern was similar in both sexes, despite limited explanatory value of the age- and height-only models in males.

Conclusions: Bioimpedance-derived phase angle may provide complementary information for interpreting treadmill spiroergometric performance in young elite athletes, especially time to exhaustion.

References

References: None.