Writing spy and action stories, the training/background of the MC is important to give him/her credibility for their actions. I have done this in chapter one, but my first chapters are filled with action to hopefully motivate the reader to keep going. Adding character backgrounds seems to stifle the flow. Likewise, to explain the MC's skills and abilities in following chapters seems too late. Also, in the past, an agent often wants to read C1, and I prefer it to be an fast flowing read. I guess the basic question is whether to flesh out character's background early or not? Any ideas?