Sunday, January 23, 2011

The Great Leucine Experiment

I've managed to stay at pretty much the same level of leanness, maybe adding a touch of muscle, over the holiday season.  That's pretty good - in the past month I've had a Christmas/ New Year's vacation, my 40th birthday (with a corresponding party), and a trip to Florida to visit my in-laws.  As you can imagine, my diet has been pretty far from perfect and my training has been spotty.

Now I'm home for the foreseeable future, and I want to lean out fairly quickly.  I am going to a 3-day karate training weekend in July (with a lot of higher-ups from my style, probably including my first teacher) and I need to be able to perform well, which means lots of hard training this spring.  I'd like to be able to increase my caloric intake for that, but I don't want to do that until I'm as lean as I'd like to be.

My plan is simple.  To lean out I'm going to cut back on alcohol (I was having some gluten free beer, wine, or margaritas 3-4 times a week this past month, which is a lot for me and a lot of empty calories!), cut back on sugar (I tend to overdo the sugar, in the form of chocolate mostly, when I'm not careful), and limit my fruit intake, especially dried fruit (it's just too easy to ingest a ton of calories and a ton of fructose with dried fruit).  I don't plan to do anything in particular training-wise to lose fat, as my regular routine should take care of it.  I'll probably also try to occasionally cycle my carbs - reducing my carb intake for a day or a few days at a time.  If that negatively impacts my training I'll likely stop doing it.  These are all good things to do for anybody, even lean people, but I'm going to be more careful about them.

I'm also going to experiment with leucine.  This is an idea I had that is a shot in the dark - I'm not sure at all that it will work, but I figured I'd try.  The idea isn't really mine, it's based loosely on Martin Berkham's work, but isn't exactly what he recommends.  Let me explain.

Leucine is an amino acid, one of the branched chain amino acids (BCAA's).  BCAA's have been famous for a while now (maybe 15 or 20 years) for their ability to induce some muscle protein synthesis.  That is, if you eat a ton of protein that has a lot of BCAA's in it, or even BCAA's on their own, you get a big uptick in how much muscle protein your body manufactures compared to what you get from ingesting a similar amount of protein that is relatively poor in BCAA's or other amino acids on their own.  This happens because the BCAA's were seen to directly affect the mTOR pathway.  More recently research has shown that it's not the BCAA's as a whole that do this but really leucine (which, remember, is one of the BCAA's).

What's so great about muscle protein synthesis when you want to get leaner?  Well, two things.  First, the more muscle you build the more you'll have, probably.  Muscle burns calories, makes your workouts burn more calories, and, really, who wants to be lean and un-muscled?  I mean, what's the point of that?  Second, protein synthesis is itself energy intensive.  Building a pound of muscle burns a bunch of calories. So keeping mTOR active more of the day should help us lean out, as long as we can do so without ingesting a bunch of calories.

Remember that I only usually eat at night.  I eat a nice dinner around 5:30 or 6:00, usually after training, then a small snack (a handful of Brazil nuts and a little chocolate and fish oil) at 8:15 or so.  Other than that it's just water and some supplements and some fish oil in the morning.

If I want to keep mTOR active all day I could drink a whey protein shake (whey is very high in leucine) 3-4 times a day.  The downside of doing that is I'd be spiking my insulin all day, ingesting a bunch of extra calories, and possibly be doing more harm than good.  That's not even remotely intermittent fasting anymore.

My brilliant (not really) idea was to ingest leucine alone several times a day, during a time when I'd otherwise be fasting.  Hopefully that will activate mTOR, keep my body synthesizing protein, burning lots of extra calories, and adding muscle to my frame without adding a lot of calories to my system or spiking insulin very much (you can't really burn fat while your insulin is high, so having chronically elevated insulin levels is the #1 biggest no-no if you're trying to get lean).  5g of leucine (the amount shown in research studies to activate mTOR) is only 20 calories, so using it 2-4 times per day won't add too many calories to my overall intake, nor should it do a lot to insulin levels.

How do we ingest leucine by itself?  Now we're in the world of supplements.  I bought a tub of leucine powder for about $21 that should be around 100 servings - enough for 30-50 days of use, depending on how often I use it.  As experiments go, not too bad.  The plan was to take 5 g or so of leucine every morning, and then 1-2 more times during the day, to get the protein synthesis machine rolling.

Disaster struck.  Leucine mixed with water tastes like... I'm not sure what it tastes like, as I've never before put anything so disgusting in my mouth on purpose.  It's foul.  It doesn't mix well.  It's quite bitter - enough so that I alternate wanting to tear my tongue out with my hands with wishing I was dead so the taste would go away.  And it lingers on the tongue.

I tried mixing it with tea and sucralose.  The result was a horrible tea flavored sea of bitterness.  Then I tried mixing it with a LOT of water (12 oz. for 5g leucine) in a shaker bottle, holding my nose and just downing it.  Still pretty horrible, but I managed to keep it down.

Can I stick to it?  I'm not sure.  It tastes really bad.  I certainly wouldn't make a lifelong habit out of it.

There are BCAA preparations on the market that are high in leucine and contain flavorings to mask the taste.  If I can't keep downing this stuff I might try one of them.  They are, obviously, more expensive, and I don't want to ingest a lot of artificial coloring agents and sweeteners (sweet tasting things spike insulin).  I'll let you know how things go.

This whole experiment may turn out to be a bad idea for a few reasons.  The energy costs of the active mTOR pathway may turn out to be trivial.  Having mTOR active all day may counteract some of the benefits of fasting all day - I'm not sure my cells will do what I want them doing (engaging repair mechanisms, cleaning out garbage proteins from the cytoplasm) if protein synthesis is ramped up.  Like I said, this is a shot in the dark at a fat loss strategy.  On the bonus side, we're talking about a non-stimulant method of possibly increasing both calorie usage and muscle building, which would be pretty awesome for dieters.

I'll update this blog with results and observations as time allows.



  1. Just hit your site after some googling, good work. How's the experiment going? I've been IF:ing for about 2 months now, and liking it. Before going paleo, I had good experience from leucine together with peptopro PWO, and lately I've been thinking about adding leucine into my immediate PWO nutrition (i eat big about an hour after lifting). I usually don't lift fasted (due to my work schedule), but i was still thinking about adding leucine 5g pre and 5g post working out. I'm very interested about hearing about how your experiment has worked out.


  2. I like BCAA's (especially leucine) on an empty stomach before a workout, I seem to experience less fatigue. As far as leucine for fat loss mid-fast it didn't do what I'd hoped - I think the protein synthesis signal doesn't do much because the process gets stopped by the lack of available amino acids. Maybe doing some bcaa's and a little protein, or an essential amino acid mix - maybe 20g - would do the trick. I haven't tried it. I do think 5g leucine pre-workout will make your workouts better, though I can't be sure it will build muscle. It's hard to verify this stuff when you experiment on just yourself (I find) because there are always so many variables! Anyway, thanks for the comment and keep me updated on your progress and experience with IF!

  3. I throw in a fasted workout maybe once every two weeks. I usually don't plan it, sometimes I just might wake up at 6 am feeling fully rested and decide to hit the gym before work, and eat my big meal at lunch time. This is when I also use BCAAs. I like this kind of morning workout (as opposed to forcing myself to wake up early), but due to my schedule its the only way I could workout fasted.

    Lately i've been eating 3 times on workout days, with 2 light meals before working out and then 60 percent of daily cals 1-1.5 PWO. I follow leangains/paleo with p40/c40/f20 on WO days and less carbs on rest days (50-80 grams). I workout around 5-6 pm, so i eat between noon-8pm-ish. I was thinking moving into 2 meals on workout days, so the workout wouldn't actually be fasted as it would happen during my eating window, but I think having 5 hours without solid food instead of 2-3 hours would work better for workouts. Even though not fasted, it would still be somewhat "empty stomach training", so leucine would fit in there pre and post WO pretty nicely. I'm still thinking about peptopro, but might start with only leucine first, as the combo is THE protein supplement that I've seen work before. Might start with only leucine for a couple of weeks and see how it goes.

    I've been eating paleo about 10 months now. I lost about 20 pounds doing LC paleo and crossfit&heavy lifting, now I'm moving more into strength work/gymnastic training and only short metcons 1-2 week. I'm 170 lbs at 6foot1, estimated bf 13-16 %.

  4. Super late response, but have you ever considered mixing the power with decaf coffee and Stevia extract?

    Stevia has helped a lot with my chocolate induced sugar spikes too.
    Except I eat chocolate in the morning.

    Two othes I found helpful and not too sugar intense,
    Water and a lil apple cider makes the taste linger less.
    Shook up with a Tsp Greek Yoghurt n water.

  5. I'm considering adding leucine to my routine, so it was interesting to read this firsthand. Thanks for sharing