I recently started this low carb diet consisting of 20 to 50g carbs per day. I am in the military and we run 4 miles 3 times a week, and 2 times a week we work on muscular strength and endurance ( ABs, push ups, etc). I also run about 4 miles after work almost every day trying to lose weight. My concern is although i havent felt entirely drained after all this exercise i have noticed that my run times are getting worse and worse and it feels harder to keep a pace. I have also noticed my heart rate picks up a lot sooner than normal. When you are performing cardio at levels this intense would i be entering ketosis with more carbs and is it dangerous to do that much cardio with so few carb? I have asked my nutritionist and she didnt have an answer and i asked my doc but he didnt really know much about low carb diets in the first place. I also ran 13.1 miles last sunday had the worst pace ever for that. After words i didnt think too much of it as cheating or not but carb wise i had half a banana and some chicken tenders samples they had out front( im pretty sure after going that far having less than 50g carbs the night before a banana didnt hurt that much.

I am on a keto diet that is under 25 carbs a day and am running 5k about 6x a week.

I would try cutting out the afternoon runs and just do the military required ones for a couple weeks. I think regardless of your carbs you are overtraining and that will only lead to injury, slower pace and burn out. Just my opinion of course....

I agree, you are probably overtraining, especially for the amount of carbs you are eating.

You can increase fat loss by restricting carbohydrates, but your energy levels and performance are going to drop if you cut them too much. Very low carbohydrate diets invariably cause muscle to be lost along with the fat. Your heart is a muscle - don't risk damage to it!

Because carbohydrates are your body’s preferred energy source, the more you reduce your carbohydrates, the less energy you will have. If your workout intensity suffers, your results will suffer.

Carbohydrates help ensure that you don’t burn up muscle for energy.

Increase your carbs for a few days until your energy level is back up. Stay "up" for a couple days, then begin "zig-zag" dieting. Three days low carbs, one day high carbs, repeat.

It also helps to limit starchy carbs to the first part of the day, have fibrous carbs in PM. Eat protein with every meal. Drink lots of water!!!

I'm going to address this statement ... Very low carbohydrate diets invariably cause muscle to be lost along with the fat. ... which is simply not true.

The body uses a combination of carbs and fat for fuel. That is why we lose fat when we cut our intake and/or increase our activity. We burn our body fat for fuel.

There are lots of good references on the internet and in books to support this. Here's a nice simple one.

http://www.dummies.com/how-to/conten...t-burning.html

Here are a few links to some info that may benefit you and have some tips:

http://www.marksdailyapple.com/overtraining/

http://www.marksdailyapple.com/how-t...-overtraining/

"....the body makes 200 grams of glycogen each day from fats and protein (and then we figure another 100 or so from your veggies and fruits). That gives you enough glycogen to fuel your brain, cruise through an average day and to be able to do a short hard workout – and then do it again the next day. However, when you train long every day (over an hour), your carb needs will increase. The key is discovering EXACTLY how many additional carb grams you need each day to refuel muscles, but also to keep insulin and fat storage to a minimum. Too few and you won’t recover from day-to-day. Too many and you’ll set yourself up for inflammation and unnecessary weight-gain."

http://www.marksdailyapple.com/prima...e-compromises/