Hi, pretty much similar here: 60 years and also 3,5 - 3,7 Watt/kg, same TSS load and a fan of 25 minute Gym session every morning (Gym Direct C8, they have also Youtube uploads). Feel great and better that 20 years ago when I wasn’t cycling that much. Actually, not so much looking for improvements but a bit anxious for the inevitable decline some day . Best and keep it up.