For the wags who responded here, a 'structured' ride is simply one that's about more than fun or getting from A to B; it may include specific mileage, intervals, a particular cadence, hill-climb training, etc. -- any or all of these. But if the ride is for a specific fitness-related purpose, over and above the fun or transport values, then it can be classified as 'structured'. Come on, if you need that explained, you need to shut off the computer and go ride -- just for fun this time, no 'structure'.