Very slow program execution speed

I can't see the option for a Release configuration on CLion like I can in Visual Studio; how do I go about doing that? I'm only seeing Debug in settings.

Otherwise, are there ways to improve the execution speed of programs created by CLion? I've been flummoxed by the fact that CLion creates programs that are over 45 times(!) slower than the same program created in Visual Studio 2017 (and executed on the same computer), and while I think that it is due to compiler settings, I do not know how to change/optimise it.

I'm a long-time Visual Studio user, but new to CLion, so apologies if I'm missing something really basic.

For reference, I'm using CLion on a MacBook Air.