Why I’m lifting weights again after a very long break—and what I’m learning about muscle, metabolic health, and aging well.
By: Robin Switzer
I recently started lifting weights again.
And when I say again, I mean after many years of what I’m generously calling “taking a break.” This isn’t the first time I’ve started “again”… but this time it is for different reasons.
I’ve spent more than three decades learning about my own metabolic health, and I’ve made some significant changes along the way. But strength training is something I let fall by the wayside.
So why am I picking up the weights again?
There are three reasons.
First, I’m thinking more about my bone health as I get older. I know how important it is to maintain strong bones, and resistance training is one of the things I can do to help support that.
Second, I want to build more lean muscle. Muscle is metabolically active tissue, and increasing lean mass can contribute to a higher resting metabolic rate. I’m not expecting dramatic changes, but maintaining muscle and supporting my metabolism are important to me.
And third? I’d like to look better in my clothes.
There. I said it.
I’ve worked hard to improve my health over the years, and there’s nothing wrong with wanting to feel good about how I look, too.
Those were my reasons for getting started again.
But as I began looking more closely at the benefits of strength training, I came across something I hadn’t really thought much about before.
Our muscles do a whole lot more than help us move.
And some of the most interesting benefits may have very little to do with what we see in the mirror.
Muscle Is More Than Strength
Most of us understand that muscle is important for strength, balance, mobility, and maintaining a healthy metabolism.
Those are compelling reasons to lift weights.
But what I find particularly interesting is that skeletal muscle is also considered an endocrine organ.
That means our muscles don’t simply respond to signals from the rest of the body. They produce and release chemical messengers of their own.
These messengers are called myokines.
And they’re changing the way researchers understand the relationship between movement, metabolic health, inflammation, and even brain function.
Your Muscles Are Sending Messages
When muscles contract, they can release signaling molecules that communicate with other tissues and organs throughout the body.
Some of these signals influence processes within the muscles themselves. Others may affect the liver, fat tissue, immune system, bones, and brain.
One of the earliest and most studied examples is interleukin-6, or IL-6.
You may have heard of IL-6 in conversations about inflammation. But here’s what’s interesting: IL-6 released by contracting muscles during exercise can have very different effects from the chronically elevated inflammatory signaling associated with certain diseases.
Researchers have identified numerous other muscle-associated signaling molecules, and they’re still learning what each one does.
This is where the conversation gets especially interesting to me.
Exercise a form of biological communication.
And the more regularly we use our muscles, the more opportunities we create for these processes to take place.
What Does This Have to Do With Your Brain?
Quite a bit, actually.
There is a lot of research involving the relationship between muscle activity and brain health.
We already have substantial evidence that regular physical activity supports cognitive health. But researchers are now trying to understand more precisely how that happens.
One possibility involves myokines and other exercise-related signals that influence the brain.
For example, scientists are studying a molecule called irisin, associated with the protein FNDC5, and its potential relationship with brain-derived neurotrophic factor, or BDNF.
BDNF plays an important role in learning, memory, and the brain’s ability to adapt.
Other researchers are investigating cathepsin B, a protein that can be released during exercise and may participate in pathways associated with memory and brain function.
Much of this research is still in its early stages, particularly when it comes to establishing the exact mechanisms in humans.
But it raises a fascinating possibility.
When we exercise our muscles, we may also be influencing biological processes that help support our brains.
For someone like me, who’s thinking more about aging well and maintaining cognitive function as I get older, that’s a pretty compelling reason to keep lifting.
The Metabolic Benefits I’m Looking For
When I began changing my health more than 30 years ago, much of my attention was focused on nutrition, weight, and improving my metabolic health.
Today I’m also thinking about maintaining muscle, protecting my bones, and staying strong as I get older.
One of my goals is to increase my lean muscle mass.
Muscle requires energy even when we’re resting, so building more of it can contribute to an increase in basal metabolic rate. The effect may be modest, but it’s one more reason I want to maintain and build muscle rather than gradually lose it.
There’s also the role muscle plays in glucose regulation. Skeletal muscle is one of the primary places our bodies use and store glucose, and contracting muscles can increase glucose uptake through pathways that don’t depend entirely on insulin.
Regular resistance training can improve insulin sensitivity, which is particularly relevant to me given my own history with metabolic health.
And then there’s bone health.
As we age, particularly for women after menopause, declining bone density becomes an increasingly important concern. Resistance training places mechanical demands on our bones and muscles that can help maintain bone strength, although the benefits depend on the type, intensity, and consistency of training.
I’m not expecting miracles from a few workouts a week.
But I do want to give myself the best opportunity to maintain my strength, mobility, and independence for as long as possible.
And yes, if my clothes fit a little better along the way, I’ll happily take that benefit, too.
It’s Not Just About How Much Muscle You Have
Here’s another important distinction.
While maintaining muscle mass matters, the benefits of exercise aren’t limited to how much muscle we can build.
Different forms of physical activity produce different physiological responses. Walking, cycling, resistance training, and other types of movement all involve muscle activity, although they don’t necessarily produce the same myokine responses.
This doesn’t mean we should abandon strength training in favor of walking, or vice versa.
I think it reinforces the importance of both.
We need to challenge our muscles to maintain strength, but we also need to use them regularly.
For me, that means getting back into lifting weights while continuing to make everyday movement part of my routine.
I’m not trying to make this complicated.
I’m trying to make it sustainable.
A Different Perspective on Aging Well
One of the things I’ve learned over the years is that our understanding of health is constantly evolving.
There was a time when I thought primarily about what I was eating and how it affected my weight.
Today, I think about metabolic flexibility, muscle, sleep, recovery, cognitive health, and the many ways our bodies respond to the choices we make every day.
I don’t have any desire to become a bodybuilder. I don’t need to lift the heaviest weights in the gym.
I just need to keep showing up and giving my muscles a reason to stay strong.
And perhaps one of the most interesting things about the research on myokines is that it gives us a different way to think about movement.
Our muscles aren’t just helping us get through the day.
They’re participating in a much larger conversation throughout the body.
Growing older is a blessing. Declining as you grow older is not inevitable. And the choice is ours.
And it’s one of the reasons I’m picking up the weights again.
Research & References
- Pedersen BK, Febbraio MA. (2012). Muscles, exercise and obesity: skeletal muscle as a secretory organ. Nature Reviews Endocrinology.
https://doi.org/10.1038/nrendo.2012.49 - Pedersen BK, Febbraio MA. (2008). Muscle as an endocrine organ: focus on muscle-derived interleukin-6. Physiological Reviews.
https://doi.org/10.1152/physrev.90100.2007 - Wrann CD, et al. (2013). Exercise induces hippocampal BDNF through a PGC-1α/FNDC5 pathway. Cell Metabolism.
https://doi.org/10.1016/j.cmet.2013.09.008 - Moon HY, et al. (2016). Running-induced systemic cathepsin B secretion is associated with memory function. Cell Metabolism.
https://doi.org/10.1016/j.cmet.2016.05.025 - Colberg SR, et al. (2016). Physical Activity/Exercise and Diabetes: A Position Statement of the American Diabetes Association. Diabetes Care.
https://doi.org/10.2337/dc16-1728
