Journal of Clinical Exercise Physiology · Jul 22, 2026
Reliability and Functional Associations of VentriJect Seismofit® VO2 Estimates
By Del Vecchio L, Climstein M
Introduction: Cardiorespiratory fitness is a key determinant of morbidity, mortality, and functional independence in older adults. Direct measurement of maximal oxygen consumption (VO 2 max) through cardiopulmonary exercise testing (CPET) is resource intensive and often inacc in community-based exercise physiology practice. Emerging nonexercise technologies such as the VentriJect Seismofit® (VS) offer a practical alternative, yet evidence of its accuracy and reliability in older adults and walking modalities is limited. Methods: Thirty community-dwelling adults (53–69 years) completed the Adult Pre-Exercise Screening System questionnaire and underwent a submaximal graded treadmill test (Bruce protocol; terminated at 85% age-predicted maximal heart rate or rating of perceived exertion of 15). VO 2 max was estimated using the VS device in duplicate for reliability. Predicted VO 2 max was compared against treadmill-derived metabolic equivalents (METs) using Pearson correlation and linear regression. Results: VS-estimated VO 2 max was significantly correlated with Bruce treadmill performance ( r = 0.45, P = .012), explaining 20% of the variance. The regression slope indicated a 0.21 MET increase per 1 mL·kg −1 ·min −1 VO 2 max. Participants were distributed across stages 2–4 METs, linking to activities of daily living from brisk walking to jogging. Test-retest reliability of VS estimates was excellent ( r = 0.98). Conclusions: VS-derived VO 2 max estimates show promise as a practical tool for predicting functional capacity in middle-aged and older adults. With further validation, non-exercise assessment may enable exercise physiologists to streamline functional evaluation and tailor activity counselling in settings with limited access to CPET.