Use it Or Lose It
Though I've been working out and strength training for the better part of my adult life, I've also gone several months without doing it, going through the same on and off cycle many people do.
Not until I started lifting consistently and a bit heavier in 2015 did I start to see change, and not until 2020 until I saw AND felt truly significant change when I added in better quality nutrition.
There's a misconception that people who work out constantly do it to lose/maintain weight or look good. Sure, these can be a couple benefits but it's not why I do it.
My primary why is longevity.
I work out to stay healthier longer;
To keep my mind and body strong now and in the decades to come;
To keep myself moving as quickly in 30 years as I do now;
To carry my own groceries into and out of the car;
To lift my own carryon up into the overhead without help;
To lower my risk of injury and chronic disease;
To keep my energy up and my stress low.
To avoid having to say the words "I can't".
Studies show that muscle mass and strength start to decrease as early as our 30's and if we don't offer them resistance and strength training, it decreases even faster. That rate of decline increases significantly after we hit 60.
A big part of the reason we see aging parents slow down is because their muscles aren't strong enough to keep up.
It's never too late to learn how to push your body in new ways or start a practice. And you don't need weights to do this - body weight exercises are a great way to challenge yourself at home: pushups, situps, squats, planks, etc.
Don't accept the "this is just what happens when we get old". It's not.