Downhill Rush

Donna Mallory is a mountain bicycle rider who is kicked off a prestigious competition in a women's race when she gets into a catfight with the jealous girlfriend of a male biker, Liam Adams.
Donna can't give up all of the hours of training she did to get in shape for the race and decides to dress up and impersonate a guy and enter the men's competition.
Liam is disgruntled when he discovers he's attracted to the guy named Don Miller, knowing he's never liked guys. He's furious when he discovers the truth and blackmails Donna into becoming his sex slave for the three days of the racing competition. In exchange, he won't ruin her biking career.
Knowing she has no choice, Donna surrenders her body to Liam, and in the process, loses her heart to him.