So my question is simple: What specifically is my body doing during this period?
And, is that too much rest? Too little? And better yet, why is so little written about rest? It feels and sounds like a good idea but why so much information about training and so little about resting if it's so important?
1. Your endocrine system rests & recovers. If the system is not overloaded, 2 weeks time is sufficient for it. In case of an overload (very little likelihood for an amateur rider) it might take even couple months.
2. Mental rest. If you turn your riding into a training routine, mental rest and “unstructured” riding is so much relaxing!
3. Let all metabolic process in your muscles complete and fully recover. Glycogen recovery takes only 2-3 days, while damaged myofibrils rebuild in approx. 3 weeks time.
Best rest routine is a recreational non-structured easy riding not longer than 60-90 min at a time. Longer time already charges your endocrine system. With such effort you can ride as many times per week as your body is “calling you for”. It could be 2, or it could be even every day. Just listen to your body, no need for conscience structure.
VERY short & strong efforts, like 5-10 sec at a time, are also OK and even recommended, however not more than 10 repeats of such type per a ride, and not more than 2-3 times per week. It will help you maintaining your so-called “hi end fitness”, or in other works aerobic muscles. More than 5-10 sec efforts or more than 10 surges per ride already [EDIT] load the endocrine system, therefore unrecommended during rest weeks.
After 2-3 weeks like this you’ll be very well rested physically, psychologically and in terms of hormones and you still will be in almost identical shape as before the “rest session”. If you don’t do short efforts over the rest weeks at all then you’ll lose some “high end fitness”, but is that a problem before going into winter months w\o racing? Probably not.