No matter how much you enjoy strength training, you probably don’t lift for the pure joy of picking up stuff and putting it down. It’s a means to an end—namely, building muscle.
So, how long does that take? The unfortunate answer: It depends.
“Every person builds muscle differently,” explains Chris Kolba, a physical therapist at the Ohio State University Wexner Medical Center.
One key factor: age. “We know that around the age of 25 or 30, we start to lose lean muscle mass, and around age 50, there’s a significant drop in the number of strength and power fibers in your muscles,” Kolba says.
In other words, not only are you losing existing muscle mass, but you won’t be able to build muscle back up at the same rate as you did when you were younger.
Plus, there are other age-related changes that can lead to muscle decline. For example, protein is essential for maintaining and building muscles, but as you get older, you don’t absorb or use protein as well. And hormone changes in both men and women can slow down metabolism, leading to less muscle and more fat.
But there’s good news too.
It’s Never Too Late to Build Muscle
Fear not. While you can’t stop your body’s natural processes, you can offset some of these changes with strength training, Kolba says. “You can always get stronger and change the trajectory of your muscle health.”
Though you might not see improvement in days, you likely will in weeks. For example, one German review found measurable increases in muscle size occur in as little as six to nine weeks of consistent strength training in adults older than 60.
Even adults with significant frailty—which increases risk for injury, illness, and disability—can see muscle improvements in eight to 10 weeks, according to a review by the National Strength and Conditioning Association.
These muscle gains might not completely change your silhouette or require new clothes, but they will transform your function, mobility, and quality of life. Over the long term, they can improve your balance and help prevent injuries.
The Centers for Disease Control and Prevention recommends people 65 and older do muscle-strengthening activities at least twice per week. If you’re up to it or as you get stronger, many fitness experts recommend doing three or four sessions per week.
New to strength training? Do what you can to start—and hang in there. The German researchers noted that people with “poor performance at the outset can achieve improvement even with less frequent training.”
The Bigger Prize: Strength You Can’t See
There’s a difference between muscle size and muscle strength. While they definitely overlap, strength has a larger neurological component, depending not only on the size of your muscle fibers but also on your body’s ability to activate those fibers. Meanwhile, muscle size is all about those muscle fibers getting bigger.
“You will always notice gains in strength before you notice gains in size,” Kolba says. “In fact, when beginning a strength program, about 80 percent of strength increases will be neurological. These progressions come almost immediately and give you the encouragement to keep working toward size changes.”
Case in point: When starting a new strength exercise, your first set might feel weak, shaky, and a little sloppy. But by your third set, you likely feel much more solid and stronger.
What happened? You didn’t magically build muscle in a course of a few minutes. Rather, the nerve cells that tell your muscle fibers to contract learned how to better coordinate the movement and keep your muscles working together.
Even if strength training has minimal effects on muscle size, it still significantly increases muscle strength in those older than 75, according to 2019 research in Geriatrics and Gerontology International.
So, while you may not see muscle definition as quickly as you would like, remember that every time you do a squat, pick up a weight, or use an exercise band, you are improving your strength. And changes are happening at the cellular level that will lead to a more toned physique bit by bit.
Stay consistent, play the long game, and you will see and feel lasting results.