The atomic mobility in the glass transition region involves timescales going from milliseconds to hours. The description of the atomic dynamics in this temperature region is complex due to the change from the ergodic liquid to the out of equilibrium glass, the inherent coincidence of experimental and material timescales and the presence of both diffusion and stress-driven atomic rearrangements. In addition, the timescales are far from being accessible by simulation. Small stress and strain mechanical relaxation experiments and X-ray photon correlation spectroscopy are unique techniques to directly probe the atomic mobility of metallic glass forming systems. This work will present recent experiments that unveil the nature, temperature behavior and aging dependence of the various mechanisms that contribute to the atomic movement in metallic glasses, which comprise: 1) drift-like movement due to free volume release; 2) athermal, stress-driven, anelastic relaxation; and 3) thermally activated, diffusion-like atomic mobility.