FUNCTION: Turn Your Blind Spots into Strengths

#1 Best Seller — FUNCTION makes healthspan measurable, actionable, and accessible, thanks to novel research spanning more than 700,000 adults over five decades.

Prof. Scott B. Fulton introduces a breakthrough insight: healthspan is most accurately measured through the everyday movements we already make, not disease or fitness, but by things like walking speed, stair climbing, balance, reach, reaction time, grip strength, cardiovascular capacity and problem solving.

Further, healthspan isn't determined by our strengths. It's determined by our weakest link. FUNCTION helps you find it, fix it, and get on track to where you could be, instead of where you are.

It also reveals your Functional Age—a more honest and actionable number than chronological age alone and simpler and more reliable than biological age calculators.

Using Fulton’s 5-Domains of Functional Healthspan, you'll create a personal healthspan snapshot from any combination of the 44 self-assessments. Each can be completed at or near home in minutes. No lab tests. No special equipment. Just clear, comparable results against healthy age and sex norms — imperial and metric.

You'll learn how to: Translate everyday movements and mental tasks into reliable healthspan indicators Strengthen specific domains without overhauling your lifestyle Track real progress over time so you always know where you are and where you’re headed FUNCTION is for anyone who wants to stop guessing, start knowing, and keep doing longer.