We measured human-induced blockage for a fixed wireless link at 140 GHz in a controlled indoor environment for a 5 m link distance with both the transmitter and receiver at the same height of 0.8 m. Humans of different complexities walked at a speed of 0.5 m/s on average and obstructed perpendicularly the line-of-sight of the link at different positions and thus, at different radius of the 1st Fresnel zone of the link. We found that the width of a person was inversely proportional to the observed mean attenuation, and for the same position two persons could produce fades of up to 7 dB in difference. Fade durations were well aligned with the width of each person and the average walking speed of the subjects, ranging from 470 to 660 ms in the median.