My coach used to say that you don't gain any fitness until after the 2 hour mark, so when I need to improve from my current condition, I shoot for 3+ hours.

At 57 years of age, my fitness seems to come on much slower than it used to. To train for Eroica, I've changed my normal rides from speed oriented to distance by riding with a slower group than normal, but putting in more miles. I'm getting close to the 4 hour mark now but I feel pretty rough near the end. At least the weather here has been fairly kind (so far), and I haven't had to resort to long, indoor trainer sessions. My biggest problem is training for hills similar to those on Eroica. It's flat prairie near home and a 60 mile ride from the house will net less than 1000 feet of climbing. I can drive about 45 minutes west to get into rolling hills that will net around 3000 feet per 60 miles, so I've been doing a lot of rides out there recently. The hills are not terribly steep (≈10% max) and no longer than a mile or so. The closest I can get to long climbs are long, straight roads into the tough winds we can have here.

I signed up for the Scalatore route, but will use the Santa Lucia route as a bailout if necessary. I'm beginning to feel like I may be in over my head.