Five months along, this issue unfortunately hasn't resolved itself. Haven't had my cortisol levels checked yet, however, I haven't developed any syndromes or diseases in this timeframe that I'm aware of, nor is there any residual fatigue, I just simply cannot ride a bike. I've cut back to one ride or less a week, but it has probably in fact worsened, limiting me to about 20 miles on flat road at ~16 mph pace. Heart rate is still elevated about 15-20 bpm, although in all this time, I'd imagine my loss of fitness would correlate with an increase in active HR anyhow. I feel great in general and mentally motivated to ride again, but just can't physically do it. If this is overtraining, can it really take one this long/longer to recover, even in the absence of any illnesses, fatigue, or soreness, or other symptoms?