I'm 40 and I feel higher T than I did at 30.
In my late 30's, I realized that I'm "smart," which is to say, I can juggle a lot of abstractions at a higher rate than most other people. But I had a disabilities, OCD, RSD (Rejection Sensitivity Disorder), Generalized Anxiety, mild Autism, and severe ADHD. Until my mid 30's, I kept it under control by lifting weights, playing sports, and a ton of caffeine by day and a ton of alcohol by night.
Becoming a father forced me to take a more sensible approach and I'm on a ton of prescriptions for those issues. Meanwhile, I switched to lower rep, higher weight workouts alternating with long runs and long bike rides which I can do with my older kids. I feel great and to your point, OP, I am not competing against anyone else. All that matters is being better than you were the day before. The real opponent is your best instincts vs your worst instincts.
Also switching from academia, where I was usually the biggest, most athletic and richest guy in the room while VC work has me in about in the middle of the pack. So I am just looking become the best VC on Earth and after that return to academia and see if a professor can play intramural. Leaders stay vigorous for as long as possible.
One of the good things about aging is that you don't feel the need to compete with other guys over small stuff. When I'm in the locker room and I have a convo with a 20 something broccoli head and he'd talking about his latest sexual conquest, I don't need to counter him, I just remind the boy to either wrap it up or at least to take PrEP.
So much has changed since I was five years old, in my own life and across the World, and yet sports and conditioning have always been a constant and considering how unstable and unpredictable the next 5-10 years will be, I'll always have ball and honestly, schooling young men with savvy and pump fakes is far more satisfying than when I was a teen and could outrun the old heads but they got the better of me in the post or off the short corner. It's an even greater escape than 20 years ago, especially as the ship of state has to now clear an asteroid belt.
So, in conclusion, I feel far more like my 15 year old self than my 25 or 30 year old self. Play and lift your heart out and trying to master whichever craft is in front of you, and fate will take care of all else.
So yes, I'm still competitive...when I want to be.
