What is real age limit for singles without beginning recession?

It's much earlier then when then this poll actually implies. If a player retires at 30-32, this means that the recession started many years before that.

The peak for the average tennis player is probably closer to the age of 25 or 26. Of course everyone is different but professional tennis with all of it's travel, exposure to sun, lack of a real off season and intense physical demands tends to age players much quicker than other sports.

The decline can be sharp, or it can be gradual but the peak physically is probably somewhere in the mid twenties.. there are some exceptions to the rule, posters like to bring up Agassi but I believe he didn't fully maximize his talent in his early years and thus failed to reach his true potential . Andre as a player was a great story of redemption and perhaps maximizing potential in ones late years but was not a story of a player who achieved all he could have achieved.

David Ferrer is another example and again, he's a guy who struggled with confidence mightily early in his career and really began to ascend around 23-25. For Ferrer it was self belief early on and it's this that cost him from reaching his full potential on tour. His peak potential though was probably still around 25 or 26 years old.