His writings on his blog except for the occasional typo or use of the word irregardless (huge pet peeve) are great and written on a very high level but very readable at the same time.
With regard to exercise, I lost 50 lbs last year without exercising at all. I sit at a computer most days or am driving my kids around. It was originally unintentional, then I wanted to make a point to friends who would have said, calorie counting and exercise. I did a number of 5 day fasts which really helped. I am now stalled and have considered adding exercise but so far have not felt it. Interestingly, in 2010 I lost about the same amount doing moderate carb and 1- 2 hours of exercise 4X per week (elliptical, road biking which I love, swimming and few reps on the weight machines). One thing, the entire time I was exercising even though I was not yet 50 I constantly had back pain and hip pain and some minor knee pain. Nothing to make me go to a doctor (which would require me to be in a stretcher!) but enough that it was annoying. After about 2 years I stopped exercising and regained almost all the weight because my workout buddy got a job that prevented her from coming to the gym and I lost incentive. The funny part was all my pain went away when I stopped. All of it. It is the classic joke, doctor it hurts when I do this, then do not do it
I have every once in a while since starting keto 16 months ago tried exercising. Each time I do, my level of soreness is much lower than it should be after exercising for the first time. A few months ago I had to help my son dig a major hole to plant a tree. We spent hours digging as it was a very big tree and did some other gardening which I never do. I had not even a twinge of back pain the next day.
The first couple of months of keto as your body adjusts are different than when you are well adapted (a theory only no science to back it up). I had all sorts of weird things flare up from getting into an argument over nonsense the first week (something I would never normally do), to having what may have been gout (may not, ACV fixed whatever it was but it took a few weeks and my toe was hurting), to morning insomnia (would wake early even if I had no appointments) and other things that I no longer can recall. Meanwhile after 16 months I rarely take painkillers because nothing hurts, still have a twinge in 1 knee but it comes and goes. I listen to my friends in their 50s complain about everything under the sun and continue to take their pharmacy of medication.
I would say take a break, let your body catch up, rest and try again in a month in the meantime do some fasting if you can