Purpose. Cerebrospinal fluid (CSF) flow has been much studied for human beings at rest, i.e. with a correspondingly low heart rate. Current measurement procedures, e.g. with MRI, can not easily collect data at higher heart rates. However, such restrictions may be circumvented by computer simulations. The goal of the present study was to characterize CSF flow at double heart rate for the cranio-vertebral region of a healthy subject though computer simulations. Methods. Several cycles of CSF flow were simulated with a 3D idealized model of the relevant region at a heart rate of 120 bpm. Velocity and pressure were calculated by solving the Navier-Stokes equations numerically. Velocity and pressure characteristics from different times and locations were then compared to corresponding data achieved from the same model with normal heart rate (defined as 60 bpm here). For simplicity, prescribed flow velocities at model boundaries were defined as sinusoidal. Results. It was found that flow velocities and pressure gradients increased substantially. Maximum velocities at the cranio-vertebral junction doubled (to more than 4 cm/s), while pressure gradients along the flow channel increased by a factor 4. Synchronous bidirectional flow also became much more prominent. Conclusions. Our findings suggest that CSF flow velocities and pressure gradients are substantially higher during typical day to day activities than during rest, which is the state commonly reported on in the literature. Our finding may have implications for our understanding of how, e.g., Chiari malformation and Syringomyelia develop.