FUNCTION: Turn Your Blind Spots into Strengths

by Scott B. Fulton

#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 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 everyday movements and mental tasks into reliable healthspan indicatorsStrengthen specific domains without overhauling your lifestyleTrack real progress over time so you always know where you are and where you’re headedFUNCTION is for anyone who wants to stop guessing, start knowing, and keep doing longer.

Genres: Nonfiction

208 pages, Paperback

Published January 13, 2026

Reviews

[Kenneth · Rating 5 out of 5]

I really enjoyed this. It's not really a book about exercise, in the sense of how to. It's a different way to think about what makes you healthy, and how to test the various attributes that keep you functional as an aging human being. Easily, at home more or less. I'll be working through these for awhile and tweaking my exercise routine accordingly.

[Patrick Tullis · Rating 5 out of 5]

This is an excellent book that uses evidence-based metrics to help you find areas of improvement for function. These metrics are based on large population studies of non-elite athletes and excludes those with medical injuries/impairments. The author is clear that he is not doctor, physical therapist, or any medical professional. I appreciate that he explicitly states that this book is to give the reader the information and it is not medical advice. He recommends talking to your medical provider with the results of these test so that you don’t get hurt. Basically, he took all this data and shows you how decline can really affect you as you age and how small improvements can protect you as you age. It really hit home for me as I’ve seen many people I care about decline physically and mentally in their 60’s. Also, he splits the data into categories for men and women.

I took many of the test in this book. I found that I need to really improve my flexibility/mobility, and slightly improve my cardiovascular area. My left shoulder mobility is similar to that of the average 80 year old man! Luckily, I identified it early with this book and I’m working on improving it.

I really, truly appreciate this author’s ability to compile all the data and to lay it out all in one place. The book and author stand in sharp contrast to all the health “influencers” that are either trying to sell you stuff or don’t really have any expertise to properly analyze studies.

[Cindy F · Rating 5 out of 5]

Function fills a huge void and is based on more research than all the expensive, inaccurate, high tech approaches. It’s an easy read and makes several important points. Ive long wanted to measure my healthspan and now I finally know! And I know how to make it better just by paying closer attention to what I already do.

Everything is very clear and doable—very factual. I subsequently orders 2 more copies for family members who are having great fun with the cognition assessments.

[Doug Dowler · Rating 5 out of 5]

Very helpful book to think about fitness/health in a comprehensive way. I am in my late 50's and this was a very helpful book to help me make sure my healthspan is as long as possible.