I bought a Large which is my usual size for tennis clothes because I like a more relaxed fit. This dress definitely runs small. Not sure an XL would fit.
i have 3 other fila tennis dresses that i absolutely love! all 3 are size small and fit perfectly. i like the fact that they are a relaxed fit, not too big but not clingy. i ordered this dress in a small and the built in bra area was so tight i barely got it on or off so i ordered the medium. it wasn't much larger in the problem area but it was too large in the bust area under the arms. and it was still difficult to remove - i thought i pulled a muscle! i hope fila hasn't adjusted it's sizing because i hope to purchase more dresses in the future.