Carbs/Fat/Protein to Calories Ratio

987Runner

Do you go with the automatic ratios set by MFP?

I cannot recall what it automatically is set at, but I changed mine to 50% carbs, 25% protein, 25% fat. I read this on a few different sites for running. I'm not a crazy marathon runner, just about 20-25 miles a week (and slowly working my way up) so I read anything above 50% carbs is probably too much. I'm looking for a combination of toning but more so working on my speed.

I'm just so confused by all the different recommendations. What ratios are you at and what are you working towards (only losing weight, building muscles, endurance, etc?)