Toning your Muscles Isn't Real

A Nonsense Fitness Term

One of the great privileges of being a trainer is getting to meet and work with many different people. Something I hear from an overwhelming number of new trainees when they describe their goals is an interest in “toning” their muscles. This is usually accompanied by sweeping gestures toward their midsection or pointing to areas they’d like to “sculpt and define.”

This, however, is one of the biggest misunderstandings in the fitness industry.

Muscles cannot change their shape independently. No amount of diet, exercise, training, massage, or stretching can physically alter the design of your muscles. Trying to make your biceps “longer and leaner” is akin to trying to lengthen your fingers. No amount of core training will magically transform the “spare tire” around your waist into visible abs.

Muscle size can increase or decrease in response to diet and exercise, but muscle tissue cannot be made more firm, defined, or “toned.”

It’s easy to understand why the term “muscle tone” has become so prevalent in the fitness world. When people start exercising for the first time, many are afraid of building too much muscle or “getting bulky,” so in an effort to sound more realistic, they use a variation of “tone” instead. It’s become a communication tool when people lack a better alternative — and there’re often valid reasons to desire what’s believed to be a “toned” physique.

As a trainer, I know what people mean when they talk about toning their muscles, and what it takes to set and reach a realistic goal. But that’s the issue with the term itself: “muscle toning” reflects a misunderstanding of physiology that must be interpreted, and because of that, it’s often misused — or even used deceptively.

What Is Muscle Tone?

In modern culture, tone has come to mean a physique perceived as having above-average muscularity and below-average body fat — essentially, the “fit” or “athletic” look. “Toning” in this sense makes building muscle sound akin to applying makeup rather than developing or strengthening organ tissue. It makes no reference to performance, isn’t measurable or scientific, and ignores the fact that appearance is often a reflection of physical health.

Physiologically, however, muscle tone refers to the slight, constant tension in resting muscles that helps maintain posture. Every muscle has a certain degree of tone, and various factors influence it. In some conditions, such as dystonia, people experience abnormal or involuntary muscle contractions — tone in this context is not at all related to muscular strength or size and this is why it has become one of the most misused terms in health and fitness.

Where Did “Toning” Come From?

Galen of Pergamon, a first-century Greek physician, was among the first to reference muscle tone, describing it as tonic activity within the framework of the ancient “balloonist theory.” Later, philosopher René Descartes also subscribed to this theory, proposing that pneuma — a spirit or fluid — flowed from the brain to inflate muscles. Despite being wrong about how muscles contract, Galen helped lay the groundwork for the modern understanding of tone through his work On the Motion of Muscles (De Motu Musculorum).

By the 1880s, the scientific journal Science made one of the earliest recorded uses of the phrase “muscle tone,” referring to the constant, slight tension present in muscles.

Fast forward to the 1960s: exercise was gaining mainstream popularity, fueled by figures like Jack LaLanne, who promoted fitness as a path to longevity. During this time, many women feared that resistance training would make them less feminine. Some doctors even warned that strenuous exercise could cause a woman’s uterus to fall out.

To counter these misconceptions, the fitness industry of the 1970s began marketing exercise to women using softer, less intimidating language — and the term “toning” took off.

By the mid-1970s, patents began to appear for products using the term, including a 1976 “spring-based thigh and pelvic muscle toning apparatus” aka, the infamous ThighMaster. Jane Fonda’s wildly successful book, Jane Fonda’s Workout Book (1981) and video, Jane Fonda’s Workout (1982) popularized the idea further, promising to help women “shape, trim, and tone.” Fitness programs like Jazzercise and Callanetics followed suit throughout the 1980s, cementing “toning” as a staple in marketing.

By the 1990s, the word had become so widespread that fitness and medical professionals began publicly criticizing it as a non-scientific, misleading term. Yet despite decades of clarification, it remains a marketing buzzword. Even today, walk through a department store and you’ll see products claiming to “tone and shape” muscles — usually targeted at women — while nearly identical equipment for men claims to “strengthen and define.”

The Alternative to “Toning Up”

For some people, simply losing body fat would create the physique they describe as “toned.” For others, building muscle would achieve the same effect. Simultaneously building muscle while losing fat is called body recomposition, and it’s a far more useful concept because it provides measurable, actionable goals.

So, the real alternative to “toning” is identifying whether your goal is to build muscle, lose fat, or recompose (both). Each goal comes with clear metrics for progress, and all can result in a more defined, healthier appearance.

The purpose of this discussion isn’t to shame anyone for using the word “tone.” It’s to clarify that its modern definition isn’t useful. It fails to define an achievable goal, and refining that goal into something measurable — like increasing strength, improving endurance, or lowering body fat — is far more productive.

Instead of “toning your abs,” a more meaningful goal would be to perform a challenging core exercise for a significant number of reps or with increasingly greater resistance while monitoring nutrition and recovery to reduce body fat. One phrase may be easier to say, but the other actually means something — and leads to better results.

Ultimately, the average person needs muscles that are strong, flexible, and fatigue-resistant, supported by healthy lifestyle habits and a balanced body composition. How you look while achieving those markers is mostly irrelevant — but in nearly every case, chasing health results in better physical appearance.