I seem to need a rest day after three or four days of riding. I expect to average around 50 mi. per day, usually making the first day a little shorter, say 35 mi. No matter how much conditioning you do before your ride, it probably won’t be enough. The first days are conditioning days. After my first rest day, I seem to be good to go for as long as necessary, although I will sometimes take a rest day after a particularly hard day, like I did on Nova Scotia when I rode across the ridge line and had to pedal down hill into a pretty stiff head wind for a total of 75 mi. You can plan your route and see where you anticipate ending up after three or four days. Portland to Astoria is probably two days, then down the coast one or two days.

It also depends on weather and riding conditions, like hills. Riding in a cold rain is very draining on me as a rider. When I rode from Seattle to San Francisco, my fourth day was a cold, rainy, hilly day from Longview to Astoria. I took a rest day in Astoria and felt fine after that.