Hi Lucalou,
I've just had a look at the first three dates for 2017 and can confirm that you wouldn't be the oldest traveller, so that's one less thing to worry about.
Given that you are still fit and active, it sounds like you would be OK on this tour but if you have any concerns perhaps a few of our members will be able to put your mind at rest, alternatively, you could give our team a call and they'll be able to talk through any concerns that you may have.
Kindest regards,
Julia