Caffeine Effects on Productivity

In a recent study, researchers observed the effects of caffeine on cognitive performance among a diverse group of participants. The findings indicated that, while moderate caffeine consumption improved alertness and focus, excessive intake led to heightened anxiety and decreased cognitive function. The conclusion drawn by the researchers was that caffeine can be a double-edged sword, promoting productivity but potentially impairing it at higher levels, thereby necessitating careful moderation.

Based on this information, complete the following sentence based on the main idea of the study: Caffeine serves to enhance productivity when used in ______ but can result in ______ when consumed in excess.