An Olympic hopeful whose dreams were cut short by addiction, Karlyn explains how sobriety gave her a second chance at athletic success and at personal happiness. But neither of those achievements came quickly or easily.    Karlyn speaks frankly about her addiction to alcohol, and the many ways that affected her life. Her book, "The Do-Over" will have readers moving from tears to cheers to nods of understanding, and is a great read for people in recovery as well as those who long to understand addiction from the inside.