You're somewhere in your mid-30's. You've passed all the milestones of being young. High school, college, your first job, several cars, maybe a city or three. Young is as young does, you think. You feel young so you are young.
One morning, you wake up, feeling like a kid. Until you pass a mirror and you jump, because there's a stranger in your house!
And the stranger is YOU. And you go, OMYGODISTHATME???? Your mind has forgotten that you have a body. Your mind has totally neglected the mass of flesh that you call home.
Years ago, a top running coach coined the term AOA, Adult-Onset-Athletes. People who never did sports in school. People who wake up one morning and realize their body is melting down into a puddle of disgusting protoplasm.
In a panic, you join a gym, get a trainer, start running, and like all type-A's, you hammer yourself into the ground.
Within a few months you build up an endurance base, you sleep great, people look at you with new eyes, because... well, you look great. But you are secretly beginning to nurse chronic injuries. Injuries, just at the very time your fitness level is going through the roof.
Winning local 10K's, 20k's, doing your first marathon. Getting admiration. Good stuff. And shin splints, ankle swelling, knee sparks, back throbs, hip pains. Despite the injuries, you push harder, faster, longer.
Your mantra is "Pain is weakness leaving my body, pain is weakness leaving my body, pain is weakness leaving my body." Wrong. Pain is injury crippling your body!
Now you hit forty. The big winning years are behind you. You try to get it all back, that rush of winning, that sweet endorphin ecstacy, but the injuries just keep piling up. Depression wraps you in its cold dank shroud of self-pity. You are injured and cant run it off.
The syndrome comes full circle. You gain, gain, gain back the weight you lost years before: And.... AaaaaaaaaAAAAAAAAAAAAA! The stranger appears in your mirror again one morning!!!! The melting protoplasm creature is rematerializing.
It's like you never even started running. Back to square zero. And you did it to yourself. But don't quit. You never quit, right?
Now it's time to start over again. Try Adult-Onset-Athleticism another way, a much smarter way.
Running pounded you into the ground? Walk, walk longer, farther, gentler. Swim, join a Y and do laps, longer, farther, gentler. Ride a bike, longer, farther, gentler. Cross-train, mix it up. Low-impact all the way.
Less can be more, if done in long doses. You're in life for the long haul, right? Exercise with patience, let your body heal, let your body become strong, the right way, over time, with low-impact regimen that your body can tolerate and benefit from for the next 40, 50, 60, 70, 80 years. Because, who knows how long your body will have to last?
Don't let your body ever become a stranger. And if it does, reward you body, and don't abuse it. It will only become a stranger all over again.
Go slow, go long, go daily. Keep changing muscle groups with cross-training. And never ignore pain.