Well I cannot run like I once did if at all so the bike is it. I generally like to ride 50 miles but I am retired and 60. Funny thing is I am not a century stalker as I know some like to get a huge long ride in at certain intervals. I have not done a century in about 5 years yet I have road over 10,000 miles this year. I would say my average ride is 50ish. I don't like to suit up and get going for less than 30 unless I have done a long race-walk before the ride. Sometimes I racewalk about 5-6 miles then go ride 25-30 depending. I find doing this I never at all need food and actually do not take any water unless it is summer. I road the last 2 days here at about 45 degrees and 55 miles each ride but no water taken. The problem with a long one at over 80 is then I really need something to keep from hitting the wall and I ride enough. I prefer the steady daily riding about same. I should mention I don't train for anything except possibly pizza, beer, donuts, and ice cream. Short fast ride have there place especially when going specific training.