How strong is the correlation between strength and muscle definition?


For example, a 170 lb (70 kg) person with defined muscles versus a less muscular person.

In: 166

Definition is a product of body fat and being lean.

However the larger the muscle, the more fat that can be spread across it without significantly softening. So larger muscles have more definition.

The world’s strongest humans are pretty soft looking.

Muscle definition is far more directly correlated to body fat percentage than to strength. Men at 5% body fat tend to have very defined musculature, but lots of professional strongmen are just big everywhere (and a LOT stronger than even most high-level athletes). Compare an NFL lineman with 15%-20% bodyfat versus a cornerback or receiver with 5%-10% bodyfat. The linemen are typically far stronger, but the receivers and cornerbacks have far more defined musculature.

Like, almost zero correlation.

Strength is strongly correlated with muscle *size* (but not 100%), definition is literally just how much fat you have.

So if you have huge muscles and have a lot of fat, you’ll be very strong but not very defined. If you have small muscles and very little fat, you’ll be well defined but comparatively weak.

Look at [strongman competitions and see almost no muscle definition]( Look at body-building competitions with extreme muscle definition, and note a LOT less overall strength.

Muscle definition comes from lowering body fat to reveal the muscles underneath.

From a biological perspective, muscle mass (actually cross-sectional area) is the only real factor that affects strength, so definition (probably over 90% due just to proportion of fat) is effectively unrelated.

That said, if you look at living humans those with enough muscle mass (CSA) to show through whatever amount of fat *are* probably stronger than similar height/massed comparables. And someone who is that combination of fat with relatively little muscle is probably weaker.

But the presence or absence or proportion of fat has nothing to do with strength.