I started on keto on 4/1 and have been very loyal. I went through keto flu and drank loads of Leanne Vogel’s keto lemonade, which seemed to do the trick. Then I reached this blissful period of abundant energy and realized it was time to start exercising. This was about 2 1/2 weeks ago that I started walking for half an hour most mornings. But now my energy level has taken a nosedive. I go to bed at 9:30, wake up at 6, and am tired, foggy, low on energy, and frequently lightheaded. Sometimes I have heart palpitations (I think that’s what it is - my heart isn’t beating faster than normal, it’s just more noticeable after minor exertion and even at rest). I also am experiencing a worsening of my hand tremor, which I’ve had for years. I had diarrhea the first day of these symptoms’ appearance, but that’s gone now. I’m drinking loads of water and keto lemonade, salting everything, and eating as much fat as usual on keto. Does it sound like a simple keto fix, a tweak to my diet, or do I need to see the doc? I’m worried about thyroid issues (none in my family though), but that’s what googling does to a person…
On keto 2 1/2 months, am suddenly lightheaded and fatigued
Could be a sign of low blood pressure. Do you have a way to check it at home? Otherwise, I vote for check in with a doctor, you may be coming down with something.
How long after starting the exercise did the symptoms start?
How many mg of sodium are you getting daily w/ the keto lemonade? Are you getting a full 2 teaspoons of salt, or 3,500-5,000 mg per day?
Yes, also don’t overdo the potassium if there’s some in your drink. Maybe you’re sweating out more salt now and need to compensate?
Hi CarolT,
Thank you for the reply. My abundance-of-energy feeling disappeared the day I started exercising, but I attributed it to the fact that I was expending more than usual. But my big nosedive was Monday. I can’t check bp at home. Maybe I’ll try Walgreens before a doctor visit.
Thanks again.
I don’t know how much I get. I salt everything I eat and additionally drink the lemonade.
Same thing happened to me, initially I had keto flu, followed by a period of smooth sailing. Then similar symptoms hit. I thought I was getting
LOADS of salt, drinking lots of bouillon every day and salting everything heavily. I dug into the numbers and measured it out, I was only actually
getting 1/4 of the recommended amount. I upped it to 3500-5000mg, which felt crazy, and it worked. Might be worth a try? I do find that it
changes daily… if I over-do it on days when not needed, that makes me feel sick too… so it’s day by day, and when I supplement I take the salt in
30 minute intervals until I feel better, so I don’t over shoot the mark. I really hope you feel better soon! 
Thank you, Alison! I’ve made it a point NOT to measure and count everything so that I can just feel like a normal person eating rather than a lab rat (Weight Watchers veteran, over here), so I’m probably vastly overestimating how much salt I’m getting.
When you say you supplement and “take salt,” do you just eat a spoonful of salt? Or put it on something? I have NOT been doing bouillon for awhile because I was feeling so good and thought everything was good. I guess I have to be more vigilant than I thought. Thanks again!
I tried the straight salt under my tongue, I just can’t handle it… so I add extra salt to my bouillon to disguise it a bit - it’s definitely not ‘enjoyable’, but easier to take
for me than straight salt under the tongue or plain salt water… maybe 1/2 t up to 1t per cup of bouillon, then wait 30 mins, then repeat until better. I totally hear you
on not wanting to measure after your WW run!
Im in the same boat. Starting to feel very sluggish and have 2 take a nap almost everyday. Thanks for mentioning this, I’m very interested in how 2 remedy it.
Found this through the search because you have described EXACTLY what I am experiencing, though I have not started exercising. 2.5 months in and have tanked. I have 1/4 sole a day, along with 1/8t no salt and 1 t Mag calm. so confusing. Lizzybirdy, how did it work out for you?
I whould like to heare , if really the salt was the solution. I am eating this way since mid November 17 and now have the feeling to fell back to my former fatigue. It is even more depressing after having such an amazing time 
If you’re exercising, your sweating. And if you’re sweating, your depleting your body of electrolytes. If you got them in balance before exercise, you will have to readjust your electrolytes now that you have added it.
Hi there Alison, i am really happy with your conversation guys, this is exactly what I was looking for. I have been into keto for five months with some spectacular results. I lost 14 kg, dropped down to 86 from 100 and I am so happy and always super energetic to the point that I am convinced to make this my life style. So all good until I started training nearly everyday 20 days ago. It is only for the last two days that I find my self with all the symptoms described in this discussion group. Another observation is that despite my keto diet is well followed, I am stack. I fluctuate in the 85-87 kg range mostly because, to my understanding, of body water accumulation. For example I go up to 87.5 or 88 for 2-3 days and then in one day all the water passes out and I am down to 85 again. Many thanks for your time!
Niko
I was advised (by a keto dietitian) to measure 2 teaspoons of salt in the morning and eat it anyway I want to throughout the day, as long as I eat it.
I agree with Alison…on keto, you need to ensure you get enough sodium!
My dietitian told me a few days ago that the sodium baseline of 2 tsp will ensure I retain the magnesium…etc etc etc.
You know I find this once in awhile. I’ve been on Keto for a few years now. Not light headed, but a brain fog, which is rare. Generally it’s I’m low on sodium. However, the fatigue thing is something I think I just got used too over the years. Not that I can’t do my workouts and put out good effort. Just there is a lack of energy or maybe it takes longer for the energy to be converted from fat, so it doesn’t feel the same.
People told me over the years that I look tired, maybe some of that is sleep. I try to get to get good sleep, but on work days it’s usually 5 to 6 hours. I think improving the sleep + salting food every day will really help. However, I would like to find a method to have more spring in my step, be more energetic throughout the day. If it ends up just being the sleep that is cool, but I don’t remember being so lethargic pre-keto on 5 to 6 hours sleep.
Damn didn’t realize this was 2 year old post for the OP, lol. Yeah, but I do feel lack of energy to do things. Drink 2 cups of black coffee every day.
I agree with @KetoRocks. Also, if you started exercising and therefore sweating, your sodium needs have probably gone up. Definitely try the 2 teaspoons a day.