17 August 2010

The Fourfold Problem of Stubborn Fat

Stubborn fat is an issue I used to write off as myth.

4 things made me change my mind:

1. Too many people complain about it for it to be ignored
2. If Lyle McDonald and Martin Berkhan worry about it, it has to be a big deal; Lyle devoted a whole book to the topic
3. Strategies professional bodybuilders used to lower overall body fat happened to effectively target this stubborn fat
4. I realized I was probably struggling with it myself

In this post, I'll add my own input to what Lyle and Martin have already shed a lot of light on: getting around the problem of stubborn fat through changes in

1. diet
2. exercise
3. (legal) drug use
4. environment (namely, cold exposure, my own theoretical approach to the problem)

Before starting, it needs to be said that these solutions are based on both human and animal studies, so while the methods for dealing with stubborn fat are old news, they should still be treated theoretically. Just a warning.

Fat loss is rather predictable and easy to achieve until near the end. I won't steal too much of Lyle or Martin's fire, but I'll briefly explain why the dynamics seem to change with stubborn fat. For those who want the technical details, read Martin's post or purchase Lyle's book.

There's evidence in the literature suggesting stubborn fat is stubborn due to

1. a problem of mobilization (getting the stubborn fat out of the cell)
2. a problem of transport (getting any freed up stubborn fat to the muscles)
3. a problem of oxidation (getting the fat into the innermost part of the mitochondria of the muscle, where it's "burned")
4. a problem of membrane fluidity of the fat cell

These problems are due to

1. the presence of alpha-2 adrenergic receptors (A2ARs) on the surface of the fat cell, and of adenosine A1 receptors (A1Rs) on nearby neurons
2. the presence of A2ARs on the inside of blood vessels
3. high carb intake
4. prior feeding habits high in saturated fat (SF) intake

The way the above factors contribute to the problem is

1. A2ARs and A1Rs act as "locks" (Martin's description) that prevent the release of stubborn fat out of the cell
2. A2ARs inside blood vessels cause the vessels to shrink in diameter, causing poor blood flow out of the areas people classically have problems losing fat from (lower abdominal and trunk region in men; thighs and hips in women)
3. high levels of muscle glycogen slow the rate of fat entry into the mitochondria
4. the more SFs consumed under conditions of weight gain, the more SFs get embedded into the membrane of the fat cell, making it more rigid and making mobilization difficult (also, a high SF intake increases the size of those fat cells

(The 2 mitochondrial subpopulations in muscle: intermyofibrillar (IMF) mitochondria, which make up 75% of the population, and subsarcolemmal (SS) mitochondria, which make up the remaining 25%.  IMF mitochondria are capable of 2.5x greater fat oxidation than SS mitochondria.)

Fortunately for us, there are several conditions we can create to improve fat mobilization, transport, oxidation, and membrane fluidity.

To improve 1) mobilization and 2) transport, we need to inhibit the A2ARs and A1Rs.

A2AR blockade is achieved by

1. fasting (in humans and rats)
2. low carb intake
3. ingestion of yohimbine HCl (an A2AR blocker)
4. cold exposure, possibly (more on this later)

On the other hand, A1R blockade is achieved by taking caffeine*.

*Yohimbine and caffeine must be dosed together to get the benefits. Stick to yohimbine HCl and avoid the herbal form, yohimbe bark (more side effects).

To maximize 3) oxidation, a low carb intake does the job nicely.

To maximize 4) fluidity, a diet high in unsaturated fats (UFs) and low in SFs during the next cycle of weight gain should be followed. In theory, lining the cell membrane with mainly UFs should promote greater mobilization, making the next round of fat loss easier.


What About People Who Lost Their Stubborn Fat Without All These Strategies?

In particular, I want to examine 3 fitness subgroups whose regimens seemed to have ignored one or more of the stubborn fat loss guidelines:

1. Martin's IF camp
2. The champions who followed Bill Phillips' 12-week Body-for-Life challenge
3. Professional bodybuilders

Without consciously addressing the stubborn fat problem, they still achieved results. Why?

Sorry to use ex post facto reasoning, but it's the only way to come closer to making sense of the whole issue.

1. Martin actually set out to answer the question himself. In short, intermittent fasting is itself great for dropping stubborn fat.

Also, Martin's estimated his carb minimum at 140-180g/day, a relatively low intake compared to the typical Western diet - low enough to conceivably improve fat mobilization and oxidation.

Also, because Martin stresses staying busy during the fast, non-exercise activity thermogenesis (NEAT) expenditure is likely pretty high. Without giving it a thought, IF followers are doing their "cardio" during the early hours of the day.

2. What about Bill Phillips' 12-week challenge?

Turns out Bill's original program involved fasted morning training/cardio. Also, because the majority of the people who took on his challenge were middle-aged working couples, they often trained in the morning for convenience. A2AR activity happens to be low following an overnight fast, so they likely had little to no problem freeing up the stubborn fat.

In his book Transformation, when trying to lean out, Bill estimated his carb intake at ~240g/day, again not that high of an intake, and perfect for our purposes. Aside from that, Bill always stressed healthy eating, which naturally eliminates high SF intake.

3. Ignoring illicit drug use, long ago professional bodybuilders instinctively landed on what's now a near-universal method of pre-contest preparation: fasted morning cardio, a low-carb, low-SF diet, and the use of yohimbine. They hit very close to the mark.

The clear takeaway is this: not all stubborn fat loss strategies need to be used for the whole thing to work, though I'm guessing that using a combination of them would maximize results.


What About Cold Exposure?

So far, changes in one's diet, exercise, and supplementation have been suggested. These 3 things have already been established and are covered at length in Lyle's book.

The idea of cold exposure was a result of my digging into human and animal studies and crossing my fingers hoping they might have some applicability here. They probably don't, but I'll go over the concept anyway.

1. At least in hamsters, prolonged cold exposure temporarily shrinks fat cell volume and membrane surface area, completely inactivating all A2ARs
2. Paradoxically, cold improves the effect of fat loss drugs on beta adrenergic receptors (BARs) that also sit on the membrane and help release fat
3. In humans, cold exposure improves mobilization of subcutaneous fat - the fat found directly beneath the skin that obscures ab definition in men
4. Cold exposure increases the activity of enzymes involved in fat mobilization and oxidation
5. The cell membranes of coldwater fish are predominantly made up of unsaturated, as opposed to saturated, fats
6. Canadian and Alaskan Eskimos have less subcutaneous fat than Caucasians (okay, they live in extremely cold climates, so the effect of the short-term exposure I'm suggesting is doubtful)

Are Eskimos shredded underneath that parka?

Most studies I've seen expose animals to a cold environment for ~2 hours at ~65 degrees Fahrenheit. Not very time-efficient. Whether exposure to colder temperatures speeds up the process of fat cell shrinkage, let alone cause any shrinkage in humans, isn't known. But it'd be interesting to experiment with.


How to Run It

1. 5-10 min walk/chores upon waking or any time prior to taking YC (the need for this portion depends on how late dinner was the evening before, since morning insulin levels become progressively lower as the fast lengthens, and the protocol works better the lower insulin levels are; some light activity before dosing YC may help)
2. Take YC. Typical dosing recommendation for Y is .2 mg/kg of body weight. This means that for a 150-lb (~68 kg) individual, he should take ~14 mg of Y. Typical dosing recommendation for C is 200 mg. Start with half the dose (in this case, 7mg Y + 100mg C) to assess tolerance for a few days.
3. Stay busy for (if you're up to it, give it a try in the cold) for ~30 min to allow the dose to be absorbed**.
4. 30-60 min of low-intensity steady state (LISS) cardio (at least 30 min to make the dosage worth it). The elevated body temperature caused by the LISS will also overcome the vasoconstriction caused by the cold, if you chose to expose yourself to it.
5. Have a protein-only meal an hour after the jog (and stay busy during this 1-hr window). The method of having a delayed meal is actually adapted from Bill Phillips' program. A protein-only meal doesn't blunt the lingering fat-burning effects of exercise, according to a study published just this year that I can't find right now.

**Alternatively, one may use the first 5-10 minutes of this period to perform a short weight training bout, sprint intervals, or anything else that will improve blood flow for the LISS portion. Though there's a delay in absorption of the YC dose, including this high-intensity portion depends on the individual response to the YC dosage. Some report unpleasant side effects from doing high-intensity activity after taking YC. This is optional anyway.

The above protocol is what I will follow during the final 2-3 weeks of my diet. This has to do with yohimbine's efficacy lasting during a 14-day study period (and it likely may have continued beyond that). The protocol will also be run alongside a ketogenic diet to improve the fat loss (yeah, I know dropping carbs this much lowers the metabolism, but what diet doesn't?)


Yohimbine, Jogging, and Short-term Fluid Retention

One warning to running the protocol is the temporary, but very real, issue of water retention that many have complained about. It can be so noticeable in the mirror that it messes with the head. Discouraged, the person blames the "fat gain" on the yohimbine and falls off the protocol.

But there's a good explanation for it all.

There are 2 factors causing the water retention:

1. The yohimbine itself
2. Jogging

1. Y is a very strong A2AR blocker. Sadly, one of the side effects of A2AR blockade is antidiuresis, or less urination. In fact, Y can reverse the effects of some drugs that normally cause more urination.

Interestingly, cold exposure causes more urination too. Guess what? Y lessens the effect. It's that potent. And because Y stays in the system for a few days, expect to give it a week or so for the extra water to flush out.

2. Runners often complain of weight gain (my roommate came to me with the same problem). That's because more fluid retention is an acute adaptation to cardiovascular exercise. My professor first made me aware of this. Some figures from the class will do a better job than words here.

 Summary: Severity of fluid retention increases with intensity and duration of the activity. The cause? Increased production of renin, serum albumin, and arginine vasopressin, also called antidiuretic hormone (ADH). The third figure shows that after 8 days of exercise, fluid volume continuously increased, and after stopping exercise, it took about the same amount of time for it to return to normal.


The message: don't sweat it. The combination of Y and increased activity will cause a possible stall (and even gain) in weight, masking the fat loss for well over a week. Give it at least this long after stopping the protocol to see the real results. 

My Previous Week's Diet (8/10 - 8/16)

Highlight meals:

1. Chipotle chicken burrito (nearly 1000 calories, according to the Chipotle Nutrition Calculator 2.0)

2. Sushi

3. Part of my post-WO meal***
1/2 cup low-fat vanilla ice cream
8 raspberries
15g raisins
4 apricots

***Inspired by Martin (from his post here).

Last weigh-in (8/9): 175 lbs
Today's weigh-in (8/16): 168.2 lbs (electronic) - dropped a lot of glycogen/water

Tuesday, 8/10
1330 kcal, 110g protein, 140g carbs

Wednesday, 8/11
1215 kcal, 85g PRO, 105g CHO

Thursday, 8/12
1470 kcal, 94g PRO, 130g CHO

Friday, 8/13
1530 kcal, 127g PRO, 120g CHO

Saturday, 8/14
~3300 kcal, lots of carbs

Sunday, 8/15
~3500 kcal, even more carbs

Monday, 8/16
1680 kcal, 151g PRO, 164g CHO


Training (8/16)

Seated military press: 155 lbs, 1x7
Deadlift: 315 lbs, 1x8
Bench press: 205 lbs, 1x8
Incline bench press: 155 lbs, 1x8
Dips: 1x8 w/ 10 lbs
Pull-ups: 1x6 w/ 10 lbs
Pulldowns: 110 lbs, 1x8
Seated cable row: 110 lbs, 1x8
DB shrugs: 100 lbs, 1x8
DB curls: 40 lbs, 1x6
DB side raises: 30 lbs, 1x12
DB front raises: 30 lbs, 1x6
DB rear raises: 25 lbs, 1x12
Machine rear raise: 130 lbs, 1x8
Seated calf raises: 50 lbs, 1x8
Standing calf raises 130 lbs, 1x8
Hyperextensions: 1x8 w/ 25 lbs
Hanging leg raises: 1x12
Bosu ball crunches: 1x15
Sit-ups: 1x8 w/ 25 lbs
Cable decline flyes: 60 lbs, 1x8
Cable decline flyes: 60 lbs, 1x5


  1. wow what an update. you sure think about nutrition a lot, don't you? haha. nice theories with a strong bibliography to support!

    also, if i interpreted it correctly, you only trained on the 16th?

  2. I have to thank Alan for that! Training, on the other hand, has been pretty basic for me all the way.

    Yup, I just do one big workout once a week. Frees me up for the rest of the week. :)

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