The purpose of this study was to evaluate the impact tailored e-mail messages, based on participants' identified needs, have on intentional physical activity. A quasi-experimental design (two groups, repeated measures) in a population of manufacturing workers (73 employees from two distribution plants of a multi-national manufacturer) was used. Significant differences were found between contemplation-staged participants in the intervention and the comparison groups. In the intervention group, 53.3% of the workers moved forward, as opposed to 19.2% in the comparison group (medium effect size = 0.353). Although both the intervention group and the comparison group increased their number of steps, the comparison group's improvement was most likely attributed to a Hawthorne effect. These results are highly promising given the small sample size and limited "dose". The intervention is one most industries could feasibly implement. Such efforts have the potential to significantly impact public health.