M_P -

Just keep in mind that, just like downhill skiing, canoeing also involves technique.  The better your technique, the less effort it takes.

For example, I took my 30-something son and son-in-law on a canoe trip a couple of years back.  I made it a "baby" trip as far as effort was concerned.  I thought it might be too easy.  My son was running marathons and my son-in-law is very athletic and always in the gym.  At double their age, at times I felt I was dragging THEM.

Also, keep in mind that a fall canoe trip can be like a fall backpacking trip.  I usually tried to finish up any hiking in the Rockies before the 3rd week of September ... too much chance of getting into some serious snow fall at altitude.  This season, I did my first fall trip to Quetico.  It felt colder/wetter than my typical mid-May trip.  Yes, it was an anomaly, but then that's weather for you!

As for me ... I've got the PERFECT body shape.  Its just that the portages are too long and someone added extra gear to my pack!   ;D

dd