What Is Functional Training?

Ask ten trainers what “functional training” means and you’ll get ten answers. For some it’s standing on a bosu ball. For others it’s carrying heavy things from one side of the room to the other. For others, any exercise that isn’t done on a machine.

Nobody has the correct definition, because there isn’t one. The word got stretched so thin it no longer tells you anything, and it’s worth saying that before you buy a class with that label on it. What is measured, in large studies with years of follow-up, is something more boring and more useful: the strength you have today predicts a fair amount of your future health.

“Functional” isn’t a medical category, it’s a marketing word

This isn’t a gratuitous attack on the term. It’s a clarification that changes what you should expect from a class called that.

In the fitness industry, “functional” originally referred to training movements (push, pull, carry, rotate, squat) instead of isolating muscles one at a time on a machine. The underlying logic is reasonable: real life doesn’t ask you to flex your bicep in isolation, it asks you to lift a suitcase, carry your kid, stand up from a chair without help.

The problem came later, when the term became a label any “different” or “unstable” exercise could wear. Standing on an inflatable disc doesn’t make you more functional than standing on the floor. Instability isn’t the magic ingredient: it’s a tool, useful in specific doses, not a universal principle.

So the right question isn’t “is this class functional?” It’s: does this class train complete movement patterns, with progressive load and correct technique? That you can actually evaluate. The rest is a label.

The data: strength predicts health

Here’s where the conversation leaves marketing and enters the data.

The PURE study (Prospective Urban Rural Epidemiology), published in The Lancet (Leong and colleagues, 2015), followed almost 140,000 adults in 17 countries for around four years, measuring their grip strength with a dynamometer. The finding: for every 5 kg reduction in grip strength, the risk of death from any cause rose 16%, and the risk of cardiovascular death rose 17%. Grip strength turned out to be a better predictor of all-cause and cardiovascular mortality than systolic blood pressure, one of the most commonly measured variables in preventive medicine.

Source: Prognostic value of grip strength — findings from the PURE study, The Lancet

Before jumping to conclusions, it needs to be said plainly: this is an observational study. It shows association, not proven causation. That people with more grip strength live longer, on average, doesn’t prove that training your grip extends anyone’s life. It could run the other way: diseases not yet diagnosed weaken the body before showing other signs, and strength drops because the disease is already there, not because the weakness causes it.

What’s reasonable to conclude: strength is a useful marker of general health, and losing it over the years isn’t a cosmetic detail.

Getting up off the floor, another uncomfortable data point

There’s another study that tends to surprise people the first time they hear it.

Published in the European Journal of Preventive Cardiology (Brito and colleagues, 2014), it evaluated more than 2,000 adults ages 51 to 80 with a simple test: sitting down on the floor and standing back up, without using your hands, knees, or any support, subtracting a point from a maximum of 10 for each support used. With an average follow-up of just over six years, each additional point on that test was associated with 21% lower risk of death from any cause.

Source: Ability to sit and rise from the floor as a predictor of all-cause mortality

Again, the same caution: it’s an observational study, and the ability to sit down and stand up from the floor combines strength, mobility, balance, and body composition. It doesn’t isolate a single variable, and it doesn’t prove that practicing that specific test changes the outcome. What it does illustrate, fairly vividly, is that strength and control of your own body through a full range of motion (which is, at bottom, what functional training done well should be about) is consistently associated with long-term health indicators.

Why muscle matters more past a certain age

There’s a physiological reason this becomes more relevant with the years: we progressively lose muscle mass and strength, and that process has a clinical name.

The revised European consensus on sarcopenia (Cruz-Jentoft and colleagues, 2019, published in Age and Ageing, known as EWGSOP2) defines it as a muscle disease: progressive, age-associated loss of strength and muscle mass that, in its more severe forms, directly affects the ability to care for oneself. The consensus focuses on low muscle strength as the central criterion for detecting it, more than mass alone, because strength is what correlates best with the risk of falls, fractures, and loss of independence. According to that same consensus, the process can start from middle adulthood (it isn’t exclusive to “when you’re old”), and inactivity speeds it up.

Source: Sarcopenia: revised European consensus on definition and diagnosis, Age and Ageing

Training strength regularly is, as far as the available evidence goes, a reasonable part of managing that process. It’s not a promise to reverse it, but it is an intervention with clinical logic behind it.

So what is functional training, in practice?

With all of that, a useful (and honest) definition would be this: training the movement patterns you use in real life (push, pull, carry, rotate, squat, stand), with progressive load and enough variety that no pattern gets neglected. It doesn’t require exotic equipment. It requires programming with judgment.

In Naü Lab Funcional, at Plaza Muray, the class is built around that logic: complete movements, load that progresses over time, and a 50-minute session where the goal is to leave stronger than you came in, not just tired. We don’t promise the class will “prevent injuries” (that depends on too many individual variables to guarantee from a group class), but it is consistent with what the evidence associates with better long-term health indicators: more strength, better body control across different ranges of motion.

If you also do pilates and are wondering how it compares as strength work, another article goes deep on that.

FAQ

Does functional training prevent injuries?

There’s no solid evidence that a group functional-training class prevents injuries in a guaranteed way. What the studies do show is that more strength and better movement control are associated with better health indicators — an association, not an individual promise.

Is functional training the same as exercising on unstable surfaces?

No. Instability is a specific tool, useful at particular points in a program, not the ingredient that defines whether something is “functional.” An exercise with your feet on the floor, well loaded and with good technique, can be more functional than one on top of an inflatable disc.

At what age should I start training strength because of sarcopenia?

The EWGSOP2 consensus describes sarcopenia as a progressive process that can start showing up from middle adulthood, not only in older adults. There’s no minimum age to start training strength: the earlier you build the base, the better.

The cheapest way to find out if this is for you: book a trial class and tell us what you’re after. Full pricing: the Unlimited package ($2,300 MXN a month) gives access to all 10 disciplines at the studio, Lab Funcional included, and coaches teach in English if that’s easier for you.