Not a bodybuilder. Simply trying to understand how my body's built.

August 1, 2010 1:44 PM

I'm neither an athlete nor obese, but am trying to lose 20 lbs while also building muscle, on a very low carb diet. My question is about depleted muscle glycogen stores while doing strength training.

I'm 5'6, 149 lbs, female, with a fairly high bodyfat percentage (27%.) I have trouble with eating carbs (mainly, whenever I eat carbs I have enormous difficulty maintaining portion size, I just go nuts and eat everything in sight) so I have found the most success in regards to satiety and portion-control in consuming 50 grams or less of carbs a day, in the form of vegetables or dairy-sugars.

I am consistently in a state of ketosis, if that matters. All in all, I estimate my total calorie intake to be around 1800 to 2000 cals a day. I only eat vegetables, dairy, healthy fats and lean meats.

In the last few months I've begun strength training with a trainer twice a week, take pilates once a week, and do 30- 45 minutes of high intensity cardio twice a week.

I've been doing a fair amount of research on bodyrecomposition.com on this subject, but I have trouble weeding through the bodybuilding-tailored answers and the science.

What I really want to know is:

1. Will strength training while eating high protein/high fat/very low carb (essentially depleting muscle glycogen stores several times a week) result in my body cannibalizing my muscle tissue to turn it into fuel? I don't want to be "wasting" my strength training sessions if they won't result in me getting any stronger. I'm not a bodybuilder, but I'd like to be strong.

2. Is the mix of eating in this fashion (high protein/high fat/low carb around 1800 cals a day) while exercising in this fashion (the mix of strength training and cardio) still a good plan for fat loss?

Any advice (ESPECIALLY any backed by science, though anecdotal is okay) is much appreciated. I've never tried carb cycling but it is something I'm willing to try, although I'm wary of the binges it might provoke.

Many thanks.

posted by anonymous to health & fitness (11 answers total)

I don't know the answer, but I think the website Mark's Daily Apple could help you.
posted by kirst27 at 2:03 PM on August 1, 2010 [1 favorite]

I should add - there's a lot on that site - a good place to start would be the Archives.
posted by kirst27 at 2:07 PM on August 1, 2010

You're unlikely to gain muscle and lose fat at the same time. Maybe you will manage this for a little while if you're just starting out, but it will not happen for any length of time. You need to be calorie negative to really be losing much fat, and calorie positive to be gaining muscle, so focus on one at a time.

Strength training will help preserve your muscle mass while you are losing fat/calorie negative, however if you are way under your calorie needs, you will still lose some muscle mass.

So, to answer your specific points:

1. No, strength training will preserve your muscle while you lose fat (or help you gain muscle if you take in more calories than you need). Not doing strength training would be a mistake. You MIGHT not get much stronger if you're not taking in many calories though, but it's still important to do.

2. Strength training and cardio with a high protein diet, while eating slightly under your maintenance calories is a good strategy for fat loss. Your body will break down your muscle for protein if it is not getting adequate protein, so the high protein part is key in preserving muscle mass while dieting.

Don't make things too complicated though. Eat as many vegetables as you want, and also take in healthy sources of protein like lean meat and eggs and go easy on the carbs while doing strength training and cardio and you'll get positive results.
posted by Diplodocus at 2:11 PM on August 1, 2010 [3 favorites]

Congratulations on your decision to take weight loss and a healthy lifestyle even further. I am a certified professional trainer in the process of becoming a registered dietician.

First, HIIT (high intensity interval training) should be limited to 20 minutes at most.

Second, you will be able to make gains in the very beginning while losing fat at the same time. However, this will change as time passes. Generally you will only be able to lose weight while cutting (calorie deficit) and gain muscle while bulking (calorie surplus).

Your questions:
1) In regards to your specific keto diet, strength and resistance training can only be beneficial. You will preserve as much muscle mass as possible while using fat as your primary source of energy. Make sure you are getting at least 1g protein per lead body mass (Around 110grams for you). While it is inevitable to lose muscle on a calorie deficit, a keto diet is an extremely efficient way of preventing muscle catabolism.

2) This is a perfect plan for fat loss. HIIT, strength training, and a keto diet has proven to be highly effective. I'd drop your calories a little more though (1600-1700).

In regards to carb cycling, consider adding a "refeed" every 7-10 days. Your body and glycogen stores will be so depleted that your workouts will start to suffer eventually. A refeed will help prevent this, and it has the added benefits of "shocking" your metabolism so your body does not adapt too quickly. Aim for high carbs, low fat on these days. Carbs from whole wheat sources and fruit would be the best.

The bottom line is you are doing everything right. Patience and persistence will get you results. I stress the patience portion as it generally takes at least 3 weeks to see the slightest change.

Good luck.
posted by telsa at 2:29 PM on August 1, 2010 [1 favorite]

Piling onto the advice that Diplodocus and tesla already gave...

1. You might find Martin Berkhan's blog leangains to be a worthwhile resource. It covers topics like the refeeds that tesla mentioned and intermittent fasting.

2. I have followed a similar diet and workout schedule and found that logging my food and workouts was important to figure out when I was not getting enough calories or protein. My experience was that there is a pretty wide range of calorie intake where my weight would stay the same; at the low end of that range, my workouts would suffer and I won't make any gains, at the high end, I was making progress and getting PRs. The log allowed me to look back and see that X many calories and Y many grams of protein coincided with lackluster performance in the gym.

3. You mention your body fat percentage, so I assume you got it measured? Weight alone isn't a very good indicator of progress, since you are mixing in strength training, and it isn't practical for most people to get hydrostatic testing done very often, so I was going to suggest a tape measure and/or an inexpensive set of body fat calipers.

Good luck!
posted by kovacs at 3:10 PM on August 1, 2010

Robb Wolf has some info on these issues. I haven't looked at all of his site, so there may be other pages that are also useful for you.
posted by kch at 3:26 PM on August 1, 2010

You might also be interested in the info from the Whole9 workout, and their Whole30 diet.
posted by kch at 3:31 PM on August 1, 2010

Something to keep in mind:

Are you familiar with the something called the "protein-sparing action" of carbohydrate? Your nervous system needs carbohydrates to operate correctly. Body fat cannot be converted into glucose to feed the brain adequately (note I said adequately - it can be used as a fuel source, but not a sufficient one to maintain nervous system health & proper function). Once you have depleted your glucose stores, your body will use protein to fuel the nervous system. "Protein sparing action" refers to the role carbohydrates play when they provide fuel to the nervous system, thus "sparing" protein from being used for this purpose. The minimum Daily Recommended Intake of carbohydrate is set at 130mg; much higher than your self-reported daily intake of 50mg.

I won't comment further because I think we're more or less diametrically opposed when it comes to nutrition, but I understand and respect your viewpoint. Just don't forget about your brain! It's the part of your body that's sending the messages to your muscles to contract, after all.
posted by pecanpies at 5:32 PM on August 1, 2010 [2 favorites]

I lost 50 lbs doing exactly what you're doing.

As far as glycogen depletion goes, I don't usually hit it until I"m at least 90 minutes into an intense workout (e.g. hitting mile 35 on a 50 mile bicycle ride).

My experience with glycogen depletion is that it's a very different kind of "tired" than I experience, for example, 45 minutes into an intense workout on the elliptical machine. The usual tirednesses sort of come as "I don't want to" or "I'm too weak". the glycogen cliff (often referred to as "bonking") feels like even if you could move your limbs, you can't put any power behind them at all. I also feel a bit nauseated when it happens.

Oh.. the other thing: the immediate consumption of heavily refined carbs; the ones you're staying away from, often fixes it in a matter of minutes.

I've stuck w/ the high-protein, low-carb diet and don't really feel like I "need" to eat carbs much. I have a very hard time remembering that if I'm doing that endurance bike ride, for example, that not only is it appropriate for me to eat those things I normally work at staying away from, it's necessary to eat them. Fortunately, i also find that in that state, the normal notion of craving and difficulty controlling portion sizes are less of an issue. I find that if I"m really glycogen depleted, I have to force myself to eat anything.
posted by desl at 8:44 PM on August 1, 2010

tesla makes the most sense.

Your brain will function just fine on ketones. Your body will only cannibalize muscle tissue if you aren't eating enough protein.

The reason people go nuts about ketones is that when you aren't doing it on purpose, it is a sign of bad medical things happening. Diabetic crisis kind of thing. But if you are doing it on purpose and giving your body the necessary fuel, it isn't a bad thing.

Here is the way I look at it, and I think I am correct. (Or at least correct-enough.):

Our bodies need fuel and raw materials. Fat and carbs are the fuel, proteins are the raw materials. Our bodies prefer carbs for fuel, because they are easier to convert to energy. Our bodies will only burn fat as fuel if carbs aren't available. First, we will burn dietary fat, and when that runs out, we burn body fat.(*) As long as we have adequate sources of either of these fuels, we will remain alive and well. And as long as we consume enough protein, and of the right varieties (essential amino acids), our bodies will use that before cannibalizing.

I think the best thing to do is keep on doing what you are doing. Hitting the glycogen-depletion wall is a good thing, because (I think) it signals the body to increase glycogen stores for the next time. If memory serves, glycogen is stored in the mitochondria. More mitochondria means a "higher metabolism". We consume energy just sitting there.

The key, however, is to measure how quickly you hit the glycogen wall during your workouts. If it takes longer and longer to get to that point, you are good to go. If, however, it happens sooner and sooner, that is a sign that your glycogen stores aren't getting replenished and you need to increase your fruit and vegetable consumption.

Also, if you find that you aren't losing bodyfat with your current routine, cut out some dietary fat.

Finally, make sure you are getting enough vitamins. Eat vitamin rich carbs, and/or with supplements.

(*) These transition points are psychologically disturbing to us. Our instincts tell us that we are running out of food, and that we should endeavor to forage and hunt, post haste. But once we are in a fat burning phase, we quickly get used to it. This is why many people fail on calorie restricted diets- we can go through one of these transition moments a few hours after every meal. But carb-restricted diets keep us in the fat-burning phase and we only have to power through the occasional transition.
posted by gjc at 7:15 AM on August 2, 2010 [1 favorite]

I am doing exactly what you're doing and trying to educate myself about how my body works just as you are. I'm not an expert by any means, but I recently read this article in the NYT which I thought was very interesting and made me wonder if there might be more of a difference between men's and women's bodies than we know. I have no idea, but thought I'd just drop it in as a data point. Good luck!
posted by triggerfinger at 1:34 PM on August 2, 2010