I am 60, was a swimmer in college, at 5-8, 145 lbs. I am now around 178, same height, with too much, imho, around the middle, but it's getting better. Last year, I joined the YMCA, had shoulder surgery, and then started really working out on cardio and weights. I have been working out swimming since 1989, US Master's team.
After surgery, I did rehab, and then started lifting weights along with cardio work. Here is my current routine. Monday, Wednesday, Friday, I go to Y, do 50 minutes hard on the elliptical with a 10 minute cool down. Then, about 40 minutes of weights, 13 exercises with 3 sets of 10 each. Just as an example, leg press I do 600 lbs. After weights, I go to pool and swim 2000 yards to loosen up (remember, I am a swimmer). Monday, Wednesday, and Saturday, I workout with my master's team and we do between 4000 and 4500 yards in 90 minutes.
Not trying to brag, I'm sure there are guys out there who do more than that, but I love it. I hated weights when I was a kid, but now enjoy it.
My body fat percentage has dropped form 25 to 20 with only a weight loss of about 10 pounds.
Oh, btw, I see providers roughly once a month, and am having, no pun intended, a ball.
I don't smoke, quit 19 years ago, but still love my beer.
My routine isn't for everyone, but it works for me. Just because we are over 50 or 60 doesn't mean we have to lay down and do nothing.
Go for it guys.
Swim