I'm thinking of entering a local time trial next year, as much to\ngive me something to aim for over the winter as anything else. How\nmuch could I expect to improve if I devote, say, 10 hours a week to\ntraining? The route is an undulating 17.5 miles, and I can currently\nmaintain 21 mph. Never having done any training before, I've no idea\nwhat to expect. Is a gain of 2 mph in 6 months realistic or am I in\nthe realms of fantasy?