Not so much fitness goals (I'm already quite "fit") as much as health goals. Two years ago I read The Real Age Makeover (about an internal makeover) and was most struck by their assertion that the three most common causes of aging are cardiovascular, immune system, and stress. I followed many of their suggestions on diet, having physical tests done, etc., in order to attain optimum health. Result, my bad cholesterol has been reduced by 10% and good cholesterol increased by almost a third in two years. The doctor also told me just this morning that my glucose levels--poor levels indicating diabetes and a host of other health issues--were excellent and rare for someone my age. I've been delighted all day!
As I've posted elsewhere, I view health as an investment (1) because health impacts mobility, freedom, and quality of life and (2) because poor health has negative financial implications. Yes, healthcare costs increase with age, but those costs and negative outcomes can be minimized by investing our time, attention, and energy into our health in the same manner we do our financial investments. At least that's how I view it.