How to toggle running Xcode project in debug or release mode by using only shortcut keys?

Debugging build: “Product” Menu => “Build For” => “Running” (shift-command-R)

Release build: “Product” Menu => “Build For” => “Profiling” (shift-command-I)

Run without building (whichever you just built): “Product” menu => “Perform Action” => “Run without building” (control-command-R)