I had ACL surgery June 20th and started Keto diet 10 days ago. My biggest concern is that I can’t exercise. I’m at that weak, fuzzy, and shake stage for a newbie. I am really struggling just to get up and go to physical therapy twice a week! The first week of Keto was great. I cooked lots of LCHF food and even a couple of LC sweets, but now I just don’t have the drive. Everyone says it’ll get better soon and to up my salt and so on, but I still have questions. Will keto work for me on almost no exercise? How long till the energy boost hits? Any advice is appreciated
Knee surgery and Keto
kib
(karen)
#2
Energy boost is unfortunately a very individual thing, some people feel it almost immediately and some people never really go there.
As far as exercise, it’s independent of keto. If you poke around you’ll find that exercise and weight loss really have an extremely small correlation - you don’t really burn that many extra calories unless you’re training for the olympics, and your body will increase your appetite to compensate.
There are loads of benefits to exercising and I do believe that being active and increasing muscle strength/mass is somehow part of the health and weight equation, but for now, heal up and don’t worry about it.
(and yes, I know it’s so common it’s embarrassing, but the number one reason for keto flu is a lack of salt and water. Your body is doing different things now, and excreting more of both, so, blah blah blah, be sure you’re covered re hydration and electrolytes.) 
PaulL
(You've tried everything else; why not try bacon?)
#3
Exercise is very helpful for reducing insulin resistance and dealing with stress, not so much for weight loss. We usually advise people to take it easy when exercising during the first couple of months on keto.
The increase in energy takes six to eight weeks for a lot of people, sometimes less, sometimes more. It’s hard to predict. It comes once the body is fat-adapted. It seems to take some time for cells accustomed to burning sugar to make the switch to burning fat. The good news, however, is that once they re-learn how to burn fat again, they can switch between the two metabolic pathways much more easily.
Give yourself some time to recover from surgery and from this shift in metabolism before returning to your regular exercise regime. Would you be encouraged if I told you that I lost sixty pounds by going keto, and the only exercise I get is jumping to conclusions? Seriously, my motto is “no pain . . . no pain.” 
So just keep calm, and keto on. “The best is yet to be.” 