Data on secular period changes in pulsating X-ray sources are compared with the rates predicted due to accretion torques on a spinning, magnetized compact object. It is found that the measurements agree with prediction if the compact object is assumed to be a neutron star. Such information can therefore be used, for example, as a distance indicator for these sources, and also to deduce the accretion rate in pulsating transient sources during their ‘low’ emission phases.