The genetics of toned muscles
Part of how ‘toned’ you look comes down to genes, notes Westcott. “Some people are born with long muscles and short tendons,” he says. And this is ideal for that super-toned look. To gauge how long your muscles are, put your elbow up at a right angle, and see how many fingers you can put in between your elbow crease and where your bicep starts. The less space you have (and fewer fingers you can fit), the longer muscle belly you have, which means the greater potential you have for building muscle size, strength, and tone. “Someone born with short muscle bellies does not have as much muscle to work with,” he notes. And while it makes sense that a tall, athletic woman would have longer bones, and thus, longer muscles, just because you have long arms and legs (or are tall) doesn’t necessarily mean you have long muscle bellies compared to your bones, says Westcott. Someone who’s short, for example, can still have a longer muscle belly relative to their bone and have just as much potential for ‘tone.’
Read: Can You Beat Genetics?
Along those same lines, we’re all born with slow-twitch and fast-twitch muscle fibers, says Westcott. When we strength train, the fast-twitch ones are more responsive and grow more easily, he says. So: “People born with a higher-than-average percentage of fast-twitch fibers respond quickly and more effectively to the strength training stimulus.”
Then, there’s body fat. “If you have a higher level of body fat, it’s like having extra blankets covering you on your bed,” says Olson. “This plays a huge role in being able to see your lean muscles.”