Acute effects of high-intensity interval training and moderate-intensity continuous training on left ventricular function in women with uncomplicated obesity

Purpose: Obesity is associated with subclinical impairments in cardiac function. Aerobic exercise has positive effects on cardiac-related parameters. However, different exercise intensities may elicit distinct acute responses, leading to chronic adaptations. Therefore, we aimed to investigate the acute effects of high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) on left ventricle (LV) function in women with uncomplicated obesity. Methods: Fifteen women performed a bout of HIIT (4 × 4-min at 85–95% of HR_max), MICT (41-min at 65–75% of HR_max), and control condition (CO) (30-min sitting at rest). Data were collected immediately before, and five (t5) and 35 (t35) minutes after the performance of each condition. Results: Significant decreases in global longitudinal strain (GLS) (p = 0.010; p = 0.002), LV ejection fraction (LVEF) (p = 0.017; p = 0.010), LV end-diastolic volume (LVEDV) (p = 0.001; p = 0.048), stroke volume (SV) (p < 0.001; p = 0.013), early diastolic inflow velocity (E) (p = 0.001; p = 0.003) and E/A ratio (p = 0.001; p < 0.001) were observed for HIIT at t5 in relation to baseline and CO, respectively. However, GLS, LVEF, LVEDV, and E wave were reestablished near baseline values at t35. LV end-systolic volume decreased after HIIT in comparison to baseline at t5 (p = 0.050). GLS and E/A ratio decreased following HIIT at t5 compared to MICT (p = 0.013 and p = 0.027, respectively). Conclusion: A single bout of HIIT promoted transient reductions in LV function that were almost completely reestablished near baseline values 35 min after exercise cessation, not implying, therefore, any risk to HIIT performance by this population. Trial registration number: RBR-3v3dqf (Registered on 07/05/2019).