I'm 6ft and 14 ish stone but I ride a sports bike all year round.
I had a great trainer (Mark) ; his advice to me was
1. Relax & bend your arms
2. Use your back muscles and don't put hardly any weight on your handlebars
If you do the above you won't have aching wrists or a stiff neck either.
Another thing I have learnt to do is to change your riding position occasionally and this relieves the stresses on vulnerable areas.
P.s. Im 49 this year and I dont have any problems with riding a sports bike.
Go for it !!!
You only have one life - don't let age dictate your passions.