Hi Frisp.. I found this thread by accident and it's very interesting. A couple of years ago I went through someting very similar. I had built up my training very quickly and was racing and doing speedwork in the same week etc, probably overenthusiastic after some good performances!. I came down with a throat/chest virus which was completely debilitating. I took numerous courses of antibiotics but it was sort of 'non specific' so didn't really respond - took almost 8 weeks to recover. Anyway, to cut a long story short, I eased off my training (still doing the odd jog), but like you, my RHR was about 5-6 bpm up on normal and more inconsisent, slow to drop etc. Didn't really feel quite right for nearly 4 months. Then spent the next 12 months with recurrent sinus, chest and throat infections and somewhat sporadic training. I even had sinus surgery and considered a tonsillectomy! I had loads of blood tests and saw numerous consultants.
I did an MSc in Sport Science some years ago, so looked up all my research on overtraining or UPS as it's now called (Under Performance Syndrome). There is no real answer as each individual is so different. Symptoms are so different in each person and there is no one set recovery plan or definition. Overtraining should probably be called 'under resting'as we all can manage different training loads, it's how we recover from hard sessions and races, and also what else is going on in our lives which makes us more susceptible to UPS. It sounds to me like you've over raced a bit - do you have any other major stress going on in your life? With hindsight, at the time I was ill, I also had a 2yr old and 4 yr old (not getting a great deal of consistent sleep) and a terminally ill father. I failed to realise the impact of this on my stress levels and ability to recover from training - it's only now (without these major stressors) that I can see how they contributed. You don't say whether you're male or female?
There are various theories, but the best advice I was given was to monitor and score a variety of 'overtraining markers' each day.. RHR is only one of them. Things like stress levels, quality of sleep, tiredness, muscle soreness etc.
Anyway.. to recover at the time, I reduced intensity completely and basically kept my heart rate under 75% ALL the time. Even if it meant walking up hills! but it worked and I came back after nearly 7 months and ran a 10k PB off no speedwork. I think at this point, you've got to take the pressure off yourself, forget goal setting, race plans and just RECOVER and LISTEN to your body. Even if this means missing races - hard as it may seem. They'll still be there another time.
This year, I have managed a year of consistent training and have ran PB's at half marathon and 10k this year, as well as representing GB at the European Duathlon Champs. However, now I don't follow a set training 'programme'. I listen to my body and periodize my training into blocks, taking PLANNED rests, rather than when I need them. I take loads of Vit C, antioxidants, a product called Elagen, and make sure my nutrition is spot on - esp recovery nutrition. Making sure I have enough protein and carbohydrate. I eat barrow loads of oranges, get loads of sleep and obsess about hand washing and using alcohol hand rubs! So far it's working...
However, I really can sympathise. It's incredibly frustrating and depressing. Take it easy and let your body recover. It will let you know when it's time to race again. I've got loads of info and links on the web so email me off-thread if you wantsazrussell@aol.com. Sorry to ramble on, but it's one of my most interesting topics! Hope you start to feel better soon.