Biologically, men peak athletically between the ages of 25 and 35. This is especially true of elite-level competitors. For everyday athletes, this does not matter in the least. Biological decline is real, but it is incredibly slow for athletic people. A disciplined 50-year old who manages sleep, nutrition, and lifting will outperform a sedentary 25-year old any day.
Unless you're planning on competing in the Olympics, I wouldn't worry about your age. "Physical peak" is relative!
