During the past few years, the market for apps monitoring traditional health and wellbeing parameters such as heart rate, levels of physical activity and sleep patterns has rapidly expanded. In this paper, we articulate how we are currently engineering an early warning system designed to support long-term brain health, termed cognitive endurance, based on such monitoring. It can be thought of as a rudimentary expert system. It will monitor physical and social activity, stress and sleep patterns and signal when these parameters are such that a person's cognitive endurance might be at risk. The aim of the system is to guide the user to adopt sustainable behavioral patterns from a cognitive endurance perspective. This paper articulates (1) what we mean by cognitive endurance, (2) how cognitive endurance may be enhanced, (3) our cognitive endurance monitoring platform, (4) our approach to calculating cognitive endurance risk, (5) specific challenges related to our approach and (6) what the long term benefits might be of successively monitoring cognitive endurance.