V̇O2peak estimation in people with overweight and obesity before and after a 14-week lifestyle intervention

PURPOSE: This study aimed to investigate the validity and applicability of a non-exercise estimation of cardiorespiratory fitness using resting seismocardiography (SCG eV̇O2peak) in people with overweight and obesity before and after a 14-week lifestyle intervention.

METHODS: The study was carried out at a Folk high school that offers 14-week courses on lifestyle changes where participants live at the school and voluntarily participate in daily lectures and activities. Sixty-seven men and women with age and body mass index between 18 and 70 years and 25-50 kg·m-2 were tested at baseline, and 52 had a follow-up test after 14 weeks. Testing included the determination of anthropometric variables, an SCG eV̇O2peak at supine rest, and a gold standard V̇O2peak test on a cycle ergometer until voluntary exhaustion.

RESULTS: Agreement analysis for V̇O2peak at baseline (n = 67, SCG eV̇O2peak: 26.9 ± 1.9 ml·min-1·kg-1, V̇O2peak: 26.6 ± 1.6 ml·min-1·kg-1, mean ± 95% confidence interval) showed a bias of 0.3 ± 1.0 ml·min-1·kg-1 with 95% limits of agreement (LoA) ranging ± 9.8 ml·min-1·kg-1. A Pearson's correlation of r = 0.78 (p < 0.0001) and a standard error of estimate (SEE) of 5.0 ml·min-1·kg-1 were found between methods. At follow-up (n = 52), body mass was reduced by 6.6 ± 1.4 kg (p < 0.0001). V̇O2peak increased by 3.3 ± 0.9 ml·min-1·kg-1 and 175 ± 78 ml·min-1 and SCG eV̇O2peak by 2.6 ± 0.8 ml·min-1·kg-1 and 93 ± 76 ml·min-1 (two-way ANOVA repeated measure: intervention p < 0.0001, method p = 0.939 and interaction p = 0.125, relative V̇O2peak). A Pearson's correlation of r = 0.37 (p < 0.05) was found between changes in relative V̇O2peak but not for absolute V̇O2peak r = 0.10 (p = 0.402).

CONCLUSIONS: The SCG method is accurate for estimating V̇O2peak and appropriate for detecting group changes in both relative and absolute V̇O2peak following a lifestyle intervention in people with overweight and obesity. Furthermore, the method can detect individual changes in V̇O2peak but not independently of body mass changes. Yet, the applicability is still limited by the relatively large variation in LoA and SEE.