ErgoSums is a brain training program built around a specific problem: people who offload thinking to AI tools are getting faster at prompting and slower at reasoning independently. The skills most commonly delegated — mental estimation, analytical thinking, critical reading, logical inference, probabilistic judgment — weaken when left unused, the same way muscles atrophy without exercise. ErgoSums targets those exact abilities through structured daily exercises designed to work them back into shape. It's aimed at knowledge workers, developers, analysts, and anyone who relies heavily on AI at work and wants to stay sharp underneath the automation layer.