As a former D1 player and returning to competition, and not merely recreational play, the very fact you are asking if your frames are viable insinuates you are wondering if you should get new sticks. Anecdotal evidence on face value is spotty. Blake and Del Potro have been mentioned for those "kept" using their racquets for the professional careers, which for Blake is 14 years and Delpo a little bit less than that. Anyone who hit at higher level will tell you racquets can break with use, especially after 4-5 years of professional training.
I think the better example for you is how many senior former pros do you see using the sticks from their peak 20 years ago? Even Roger Federer has upgraded from the stick twice, from the PS85 he used as a 17 yr old, and he's a professional athlete with as much talent as anyone else, if not more. There are players who feel they are at the pinnacle of their prowess won't be changing racquets because they want the feel. I'm pretty sure it's more the psychological factor of having to change to something that feels foreign enough that they can't get their head around. James Blake was battered around post 2008, even though he still had his speed and athleticism. Cos the flexy racquets slowing his game down a few mph have kept him from losing to players? We'll never know now.
Coming back into competition and prepping means you'll be hitting a lot, it's a great time to find a stick that allows you to swing the same and maybe give you a few RPMs and mph age has taken away from you, while working less hard. I was stubborn like that, and stuck with the PS90 waaayyyy too long, but I could get replacements that were 95% similar. One time, I played 3 3 set 2.5+ hrs singles matches in 2.5 days against guys 10-15 years younger than me, and I was hurting from having to hit out so much. The next week I started searching for 95s and went with 6.1 95 16x18, and while I wasn't accustomed to the new stick, I physically could play hard longer cos I wasn't working as hard. The extra 3-6% of pace and spin, especially on serve, made a significant difference.
I'm not advocating you switch every 2 years, but after 20 years of service, I think it's worthwhile considering, if budget isn't an issue. This is from 1 former D1 player to another!
Is there any test one can perform or examination to determine if a racquet is still fit for play? I'm planning to return to competitive tennis next summer at the age of 56 and still use my trusty iPresitge MPs from 2001. I had a total of three summers during the last 20 years where I played roughly 10 hours per week. Other than those summers I hit sporadically with a few people, but nothing too intense. I was a DI scholarship player who played with power back in his heyday, but no longer play with such power. I have never abused my racquets. Is there a way to determine if my racquets suffer from micro-cracks or if my head has lost stiffness?
