Ok. There is "bad" cholesterol (the LDL), the "good" cholesterol (the HDL), Triglycerides, and some others that I'm not going to get into for simplicity's sake.
To start, the LDL, or "loser" cholesterol is the main culprit of heart disease. This is that number that we, as doctors, freak out about. The LDL should be less than 100, ideally. If you do not have diabetes or any other medical problems or family history of heart disease, we say less than 130. If you have diabetes, <100, for sure, and now we are saying <70 if we can get it there safely.
The HDL is the "happy" cholesterol. HDL cholesterol actually takes the bad cholesterol from the arteries and transports it to the liver to be processed and removed. So, HDL>60 is said to be "cardio-protective", while an HDL<50 in women and <40 in men may put you at a higher risk of heart disease. To improve your HDL, avoid smoking and maintain a healthy weight.
Triglycerides store unused calories, and high levels typically correlate with eating a lot of starchy foods (carbs) and fatty foods.Also, people with uncontrolled blood sugars also typically have high triglyceride levels. Triglyceride levels should be <150.
The "total" cholesterol is basically the total of these mentioned plus a few not mentioned. The total cholesterol doesn't mean too much without the breakdown of the components. So, focus on the breakdown, and "know your numbers"!
HDL >60 in women, >50 in men
Also, just because you are fit and in good shape does not mean you have nothing to worry about. A very large part of cholesterol a lot of times is genetic, and there is not much you can do about that, unfortunately. Regardless, whether you are thin, heavy, in shape, or not....get it checked!!