Too few carbs, especially when exercising?

lchf
carbs
exercise
muscles
food
(Nick D'Agostino) #1

Hi all,
I’ve been very successful with IF and LCHF. However, it seems that I sometimes run into trouble when I add exercise into the mix. I’ll feel week, my cravings will change, or I’ll get a headache that is identical to when I used to be carb-addicted and was low on carbs. (It’s not salt. I’ve made sure to have enough sodium.)

One time, I even got exceptionally unwell and was immediately “cured” by about 5g of sugar.

I’m wondering if it’s possible to have too few carbs on a keto diet, especially when exercising. Is this b/c the liver can’t produce enough glucose for the brain or perhaps if the brain hasn’t completely adapted to ketones (does it ever use 100% ketones?)? Has anyone else had any experience with this?

Perhaps another question, I struggle with determining how much protein I should eat if I’m doing some simple strength-building exercises like crunches, push-ups, pull-downs, etc.

Thanks!

(This is my first time posting. My apologies if I goofed up on any of the etiquette.)

(Lonnie Hedley) #2

Our bodies don’t need any carbs. Our brain can get the glucose it requires by gluconeogenesis. Short answer, no, you can’t have too few carbs. Even while adding exercise.

(Olivia) #3

It depends on whether you’re doing aerobic or anaerobic exercise, which in turn effects how your muscles produce ATP. It can be made with creatine phosphate present in your muscle cells. This ATP source lasts for 5-10 s. Next is the glycogen/lactic acid route, which is an anaerobic process. Lastly, the slowest path for your muscles to produce ATP is the aerobic metabolism, which uses fatty acids if all glycogen stores are empty.
So, during anaerobic training your muscles would benefit from glycogen. If, however, you’re a runner (not sprinter) you’ll be fine just burning fat.

(Michael ) #4

It takes time to adapt. I had the same troubles and now do hiit and weight training in a fasted state. Nevermind sugar, i typically haven’t eaten anything in 14+ hours when exercising. Give your body time to adapt and you should be able to regulate blood sugar properly. Also, check your blood pressure as it can dip low with keto, especially if not getting enough salt. If it’s too low, you’ll get dizzy and don’t want to fall in the gym. Some people do say that they never feel right in the gym without carbs. For me, it was just an adjustment period. I don’t think I perform quite as well now, but I’m not an elite athlete. So, a small tradeoff in performance for better health is acceptable to me

(You've tried everything else; why not try bacon?) #5

Dr. Phinney recommends a cup of bone broth about half an hour before exercise, so as to make sure you’re well-hydrated, and help you avoid the symptoms you mention.

#6

Just sounds like your not fat adapted yet. Hard to tell whats going on without more details but I’m usually always at 20 or below, in the gym 4-5x a week, lifting and cardio without issue, I also keep that schedule when I do my fasts which is usually a week most of the time. Protein can be tricky most people have to play with it but if your looking to BUILD muscle you’ll be a little higher. I’ve had no issues improving strength so far in the 80-100 range. The typical starting point for many is 1g protein per kg lean body mass.

#7

Sounds like you had either a hypoglycemic or a hypotension episode. I’ve experienced both, mine are are associated with exercising while doing EF. It can happen even after being fat adapted. It’s transient, even if you do nothing, the body will self correct. Eating anything (regardless of macros) will help. Eating sodium will also help.

(Nick D'Agostino) #8

Thanks, all, for the tips. Let me add some information.

I have jogged significantly while fasting before. I have done a limited amount of other exercises while fasting. The vast majority of the time, I haven’t had a problem (though I feel that I have less “power” when fasting).
I was plenty hydrated and had plenty of sodium in my system.

When I had this particular “acute” problem, I had fasted all day on a Friday. Saturday morning, I had a few-mile jog on a treadmill. Then, I spent all day walking a significant amount. Throughout the day I had a low-level headache which I’ve learned is indicative of low blood sugar for me.

When I got home at the end of the day, my headache increased to be severe, and I felt nauseated and weak. I tried eating fats & protein, but my body did not want to do that. My appetite was finding the food repulsive. Even so, I had some food, and it didn’t help.

Then, I had just a few grams of sugar, and I felt better within minutes.

This was certainly some sort of hypoglycemia. I’m trying to figure out why this happened on this occasion.

(Lonnie Hedley) #9

Because sugar is crack? Crack addicts have similar symptoms. Dosing “helps” them too. :smile:

(Ken) #10

Of course occasionally eating carbs such as fruit is normal and healthy. It is part of our Evolution, as is why ripe fruit is so tasty.

It’s especially totally fine if you want to have some around your training, in the context of overall fat based nutrition.

I have a hard time visualizing my paleo ancestors, when coming upon a source of ripe fruit, to exclaim “Wait, don’t eat that stuff, let’s have some bone broth instead!”.

(ianrobo) #11

have you got any HR data for a run we can look at this ? As @PaulL said then Salt is key up it a lot and read what Steve Phinney says !!

Also heard of the MAF method ? take a look at it

(Nick D'Agostino) #12

I do not have any HR data for you, but I am very well aware of my HR, and it wasn’t particularly elevated. I long ago discovered that my endurance goes up dramatically if I’m at a lower HR, which I believe is what MAF notes.
I took more than enough salt. It was not the problem. I have had too little salt in the past, and I supplemented this time, and this was not the same reaction.

Thanks