Eficiencia metabólica y demanda cardiovascular: análisis comparativo entre Yoga y HIIT en varones de mediana edad

Introduction: Identifying sustainable exercise modalities that match the cardiovascular benefits of High-Intensity Interval Training (HIIT) is a current challenge to improve adherence to physical activity. Objective: To compare the hemodynamic response and metabolic efficiency (kcal/h) between self-managed sessions of HIIT and dynamic Yoga in physically active middle-aged men. Methodology: A cross-sectional observational study was conducted on 153 adults (Yoga n = 86; HIIT n = 67). Acute responses were quantified in an ecological environment using smartwatches with optical sensors. Welch's t-test, Hedges' g, and a multiple linear regression model with an interaction term were applied. Results: No evidence of statistically significant differences was found in metabolic efficiency (721.02 vs. 735.92 kcal/h; p = 0.221) or mean heart rate (143.51 vs. 145.58 bpm; p = 0.371), with trivial effect sizes. The strong correlation (r > 0.90) between heart rate and caloric expenditure evidenced a circular artifact inherent to the devices' predictive algorithms, with no interaction by modality (p = 0.586). Discussion: The findings challenge the traditional classification of Yoga as a low-intensity activity, placing dynamic styles in comparable ranges of cardiovascular demand during self-managed practice. Conclusions: Under ecological conditions, dynamic Yoga presented an acute cardiometabolic demand statistically similar to HIIT. It represents a relevant metabolic stimulus and a viable alternative with lower mechanical impact, requiring future experimental trials to confirm chronic adaptations.