Association of phase angle and running performance

A high phase angle derived from bioelectrical impedance analysis has been linked to a high level of physical activity. However, it is unknown whether a high phase angle is related to running performance.

We included all subjects who participated for the first time to the Course de l'Escalade between 1999 and 2016, a yearly city run occurring in Geneva. The subjects underwent a measurement by 50-kHz tetrapolar bioelectrical impedance analysis (Nutriguard®). Running time was converted to running speed in km/h. Results are shown as mean (SD) and as frequencies. We performed sex-specific univariate and multivariate regressions, adjusted for age, body mass index, categories of running distance and year of measurement, to evaluate whether the phase angle is associated with running speed.

We analyzed 2264 subjects (1025 women and 1239 men). In univariate regressions, phase angle was significantly related to running speed in women (coeff 0.52, 95% CI 0.35-0.67, p < 0.001, adjusted R² 0.037) and men (coeff 0.57, 95% CI 0.42-0.73, p < 0.001, adjusted R² 0.039). Multivariate regressions showed that the phase angle was still significantly associated with running speed in women and men (p < 0.001 for both models), with an adjusted R² of 0.262 and 0.282, respectively.

The phase angle is positively associated with running performance in men and women. It remains to be demonstrated if this association reflects the benefit of regular training and whether the phase angle might be suitable to monitor improvements in running performance. CLINICAL TRIAL REGISTRY: clinicaltrials.gov, identifier: NCT03400761.