@bkkboy, I am also a bit older. In fact in May 2016 I was 74. From my training I had learnt three things:
1) To get the most enjoyment start early, it allows you to take options later in the day. I started from S-Jean just before sunrise, and I was about the middle of the pack. I go to bed wearing just about everything I will start with and my pack just needing a final closing.
2) I have found it best for me, to dress for mid morning. Usually this will mean a short sleeve (merino) top and gloves. Most people starting out that morning were dressed for the morning chill and most had to stop a a few kilometres to take stuff off, open their pack, swap and close the pack: ?and getting a chill in the process?
3) Walk at a constant pace: shorten or lengthen your stride for steep or flat sections. On the steepest section my stride would be 100mm to 150 mm (4" to 6") - in other words, for the moving foot, the toes would be 100mm to 150 mm in front and the heel some where w=between the heel and toes of the static foot. And I would breathe in on one footfall and out on the other - my breathing acted as a metronome.
Using those techniques, just like the tortoise, I passed so many people and was passed by one. I had three stops:
- about 2 minutes at Orisson to ask about the weather;
- less than 1 minute at "last sello caravan" as the throng meant a delay and the wind was chilling;
- "comfort stop" in the now sunny forest a few km before Roncevalles.
I was at the albergue before it opened for bookings, along with two or three other early birds.
Two days later I was in the albergue at Zalbadika. Several Sacred Heart sisters offer a pastoral and late evening service. At that the "youngsters" wanted to know how I was so fast - I told them about techniques three. Early afternoon the next day I was the other side of Pamplona looking at the windmills stretching along Alto del Perdon when another callow you approached saying he had heard I was the "fast one", was this correct?
If you don't have hills that you can train on, try getting regular access to high rise buildings. First without gear: just getting the muscles in the upper leg (knee to thigh/groin) used to the extra work. When you can do, say, 10 floors with ease then start over with all your gear on your back and aim for 10 floors with ease again - 10 floors is at least 30 metres and nearer 40 metres of elevation gain, but the effort of lifting you foot to the next step is quite high, especially when fully laden.
All I can counsel for you is "do it your way". But be match fit for the many days ahead
Kia kaha, kia māia kia manawanui (take care, be strong, confident and patient)