FUNCTION: Turn Your Blind Spots into Strengths

by Scott B. Fulton

Do you know where your healthspan stands today? Would you like to be able to measure and track it with confidence? Thanks to new research, there’s now a way—FUNCTION shows you how by turning what your body and mind can actually do each day into a clear, actionable measure of Functional Age.

Grounded in longitudinal studies of more than 700,000 adults over five decades, this portfolio-style view of functional capacity explains why some people move and think years younger than their birth certificate—and how you can, too. Instead of one-size-fits-all tips or abstract scores, FUNCTION gives you a personal healthspan scorecard built from simple self-assessments you can perform at home in minutes, with no lab work, wearables, or special devices required.

Across five domains of physical and cognitive ability, you’ll complete 44 research-based tests that reveal your strongest reserves and your hidden blind spots, then show how your results compare with healthy norms for your age. You will see your Functional Age, understand why it outperforms bodyweight, step counts, and biological-age estimates as a predictor of how well you will live, and learn how to lower that age using activities you already do in everyday life.
In these pages you will learn how everyday movements and mental tasks into reliable indicators of current and future healthspan.Turn your results into a simple, repeatable plan to strengthen specific domains without overhauling your entire lifestyle.Use periodic re-testing to track real progress over months and years, so you always know whether your choices are adding capable years to your life.FUNCTION is a practical, evidence-based field guide for anyone who wants to stop guessing about aging, see their true capacity in black and white, and build a future they can count on—one they are strong enough, sharp enough, and confident enough to fully enjoy.

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.