OBJECTIVE: Increasingly, workers in the service, welfare, and health care sectors suffer adverse effects (ie, depression, burnout, etc) of "low-energy syndromes." Less is known about energy-based outcomes among knowledge workers. This study aimed to identify determinants of self-rated energy in knowledge workers and examine how these determinants change over time.

METHODS: In collaboration with a large union and employer federation, 317 knowledge workers in Sweden responded to the health and productivity survey three times.

RESULTS: At each assessment, worry, satisfaction with eating habits, and work-effectiveness were predictive of energy levels; however, only work-effectiveness covaried with energy over time.

CONCLUSIONS: This study suggests that perceived work-effectiveness is an important factor in preventing knowledge workers from experiencing "low-energy syndromes." Lifestyle factors also play a role. Therefore, multifaceted interventions for increasing energy are needed.