I hope that someone who has experienced this problem can help me out. I've been training for the Firecracker 50, a 50 mile race in Breckenridge CO. When I go on training rides my first few miles are awfull. This is a problem even if the first few miles are relatively flat and I am going at race pace. I feel tired and my breathing is ragged. After a few miles I seem to suddenly improve and can do great for the next 35 to 40. (Of course over 40 miles or so I imagine everyone gets tired.) The first part of this race is an extended climb. It's not too steep but it lasts for several miles and I'm sure I will struggle. Keeping in mind that I don't want to fall too far behind to start and I don't want to tire myself out riding a few miles before the race what should I do to warm up? Thanks in advance.