CMYK Gradients

Does anyone know what the deal is with CMYK gradients? In InDesign and Illustrator whenever i’m designing something for print and i want to use a gradient it shows up weird. The gradient seems to go to my first color to grey to my second color. In RGB it goes very nicely from color1 to color2 but in CMYK it’s muddy in the middle. It prints that way too. Anyone know why?