Adaptive workstations enable the automatic individualization of workplace parameters. This paper proposes an algorithm to plan the adaptive adjustment of the height of large planar work objects during an assembly cycle to reduce physical stress from awkward postures. A simulation was conducted to evaluate the impact of this algorithm in a car door assembly use case with a prototype of an adaptive workstation. Two modes, focusing on either workload reduction or efficiency retention, are compared to the system in a one-size-fits-all configuration. The simulation results suggest that adaptive systems may homogenize physical stress levels in the workforce and that the mode of adaptation has an effect on the system’s efficiency.