Small-angle X-ray scattering (SAXS) is an experimental method for structural characterization of biomolecules in solution. As SAXS measures averaged low-resolution scattering intensities, the sparse information obtained is not sufficient to reconstruct unique atomistic models. We integrate this information into molecular dynamics (MD) simulations using computationally efficient structure-based models (SBMs). Based on a dynamic fit of scattering intensities, such simulations produce reasonable structural models in agreement with the target data. Simulations are faster than explicit-solvent approaches by more than two orders of magnitude and achieve comparable accuracy.