PurposeThe angles of thoracic kyphosis and lumbar lordosis determine the spinal alignment in the sagittal plane. The aim of this study was to compare the thoracic kyphosis and lumbar lordosis of male and female yoga practitioners with non-practicing participants and to determine the possible dependencies between sagittal spinal curvatures and somatic parameters, time spent on yoga exercise, and undertaking other physical activities in yoga practitioners.MethodsThe study involved 576 women and 91 men ages 18–68 years (mean = 38.5 ± 9) who were practicing yoga, and 402 women and 176 men ages 18–30 years (mean = 20.2 ± 1.3) as a control group. The angles of thoracic kyphosis and lumbar lordosis were measured using a Plurimeter-V gravity inclinometer.ResultsThe two-way ANOVA demonstrated the influence of group (p < .0001) and sex (p = .03) on the angle of thoracic kyphosis, as well as the influence of group (p < .0001) and sex (p < .0001) on the angle of lumbar lordosis. It was noted that yoga practitioners had less pronounced thoracic kyphosis and lumbar lordosis and were more often characterized by normal or smaller thoracic kyphosis and lumbar lordosis than students from the control group. In yoga practitioners, the angle of thoracic kyphosis was positively correlated with age, body mass, BMI, and undertaking other forms of physical activity. The angle of lumbar lordosis was negatively correlated with body height and body mass.ConclusionsThe results suggest that yoga exercises can affect the shape of the anterior-posterior curves of the spine and may be an efficient training method for shaping proper posture in adults.