By SHAPE Editors
This article first appeared on the U.S.-version of SHAPE.com
Think they’re bulky and unattractive? Don’t worry, women’s bodies are generally not wired to be as muscular as men’s, so there’s very little chance you’ll end up looking like Arnold and Beckham. In fact, more high-profile models like Alessandra Ambrosio are embracing ‘ strong and toned’ rather than ‘thin and wispy’.
That’s because muscle keeps your metabolism revved, takes up less space than fat, protects your joints, and allows you to lift heavy objects without the help of a guy (so he can’t say you’re needy).
Here are more surprising facts (and reasons to include strength training in your sweat routine):
Without muscle, your bones, joints, and ligaments are considerably more vulnerable to age–related decline and injury, according to Dr. Kenneth Hansraj, an orthopedic and spinal surgeon based in New York City.
Building core strength in particular protects your spine, which is key to a healthy musculoskeletal system. In fact, a healthy, straight spine is pretty much the definition of youth and anti-ageing, Dr. Hansraj says.
Did I lose you at marshmallows? Stay with me. Muscle is much denser than fat. So if, for example, 500 grammes of muscle is about the size of an apple, the same amount of fat is the equivalent–size-wise–of 500 grammes of marshmallows, according to Dr. Hansraj.
Still confused? Imagine how many marshmallows you would have to pile on a food scale to have it progress to 500 grammes. Probably a lot: at least one full-sized bag. Now imagine the space five of those bags would take up (2.5kg of fat) as opposed to the amount of space five apples would take up (2.5kg of muscle).
It’s a lot less space—and a lot less marshmallows. For an even easier and entirely fruit-focused analogy, 500g of fat is about the size of a grapefruit, and 500g of muscle is about the size of a tangerine.
Muscle is metabolically active tissue, which means it demands more fuel for support. While protein is the primary source of fuel (hence body building’s obsession with the stuff), this also means that more of the total calories you eat are burned as fuel rather than stored as fat.
How many more? About 50 for every 500g of muscle you add, according to Hansraj. That’s about the calories in a single Oreo cookie, two Hershey kisses, or half a glass of Merlot. It’s not a ton, but it does mean that if you watch your overall calorie intake, you can have little treats here and there—totally and completely guilt-free.
4. Muscle Keeps You Sane
While the jury is still out on whether it provides a bigger mood boost than cardio, if you weight train at a high enough intensity, you can experience an effect similar to the runner’s high, when your body releases natural pain-relieving opioids, says Richard Hammer, associate clinical professor of pathology and anatomical sciences at the U.S.’s University of Missouri School of Medicine
And according to Dr. Hansraj, weight-training leads to an improved androgenic hormone profile. In essence, a better balance between male and female hormones, which leads to a more stable mood.
According to a study published in the Journal of Strength and Conditioning Research, people who lift weights are 37 per cent less likely to have metabolic syndrome—a cluster of risk factors linked to heart disease and diabetes.
How? Muscle helps your body process blood glucose more efficiently, according to Dr. Hammer, which helps lower risk of developing type 2 diabetes. It’s also associated with a smaller waist circumference (less marshmallows!), which is an indicator of lower LDL (bad) cholesterol, which in turn equals a healthier heart.
Not comfortable slinging super heavy weights? You can still reap the many benefits of building muscle. A study published in The Journal of Applied Physiology found that participants still experienced strength gains when lifting lighter weights as long as they worked their muscles to fatigue.
This is good news, since the 20-plus pounders (9kg and above) tend to reside in the serious weight training part of the gym, which can be intimidating, eye roll inducing, or just too grunt-filled to be a fun place for ladies who lift.