by Clay Hyght, DC T-Nation
In this article I'm going to offer five nutritional strategies five nutrients and one elegantly simple dietary strategy that will help improve your insulin sensitivity.
I believe in teaching as opposed to telling. So let's briefly review what it means to have "good insulin sensitivity." This way you'll be armed with knowledge that will help you make sound dietary decisions.
What Exactly is Insulin Sensitivity?
What do bouncers and insulin have in common?
No, there's no punch line bouncers and insulin actually are rather similar. Allow me to explain.
The cells that make up our body are much like night clubs some welcome anyone in with open arms, while others are quite exclusive, to the point of having to "know someone" to get in.
When I was a bouncer in college, I soon realized that one of the perks was the attention I got from girls who knew I could get them and their friends in for free, and without having to wait in line.
But because I obviously couldn't let everyone in without paying, I had to make the tough decision of whom to grant VIP status and whom to tell, "Sorry, can't help ya."
Our muscle cells are rather picky about who they let in. Nutrients can't just be cruising through the bloodstream and decide, "Hey, I wanna go inside that muscle cell and see what's happening." No, muscles don't roll like that.
To get inside a muscle cell, it really helps if you can get insulin on your side. If you can, you're pretty much assured of gaining access, because insulin is like the head bouncer at a club. If you're tight with him, you're in.
Although bouncers are notoriously callous, they're still humans subject to human emotions. If you happen to catch your favorite bouncer after his stripper-girlfriend just cheated on him, he's likely to be quite insensitive to your request for entry, thus not as likely to let you or anyone else in.
On the other hand, catch him after his favorite football team just won the Super Bowl and you're likely to find him more amiable and sensitive than usual thus eager to let you, your friends, and your friends' friends into the club at no charge.
If you follow and understand this bouncer analogy, then you understand insulin sensitivity.
Sensitive bouncers let more people into Club Hotspot. Sensitive insulin receptors let more nutrients (i.e., glucose, creatine) inside Club Muscle Cell to get the anabolic party started.
With that fundamental understanding of insulin sensitivity, let's take a look at five ways to maximize your insulin sensitivity.
If you've been around sports nutrition and the iron game a while like I have, chromium might seem a bit old school, but I'd say old's cool is more like it! Just because it's not "cutting edge" doesn't mean it's not effective.
Taking supplemental chromium has been shown repeatedly to improve insulin sensitivity and glucose tolerance, even to the point of reversing type II diabetes in many people (1). Thus, as my old clinical nutrition professor pointed out, apparently a chromium deficiency can actually lead to type II diabetes.
In fact, chromium is so synonymous with insulin sensitivity and glucose tolerance that some actually refer to dietary chromium as Glucose Tolerance Factor (GTF).
Doses of between 200 and 600 mcg per day seem to be both safe and effective.
As with any mineral, taking too much can lead to as many, albeit different, problems as a deficiency. So don't think "more is better" when it comes to supplementing with chromium or any other mineral.
I tend to use what I feel is a "common sense approach" to chromium (and any mineral) supplementation if you haven't taken it in a while, then you're likely deficient. So it makes sense to fill in this nutritional gap by taking it as a supplement, maybe temporarily at a dose that's on the higher end of the scale.
Then, after a couple weeks or so of supplementation, reduce the dose to the lower end for maintenance purposes.
Also consider, from time to time, having a "supplement holiday" and stop taking the mineral all together. I find it works well to have the supplement holiday when you're actually on vacation or traveling. That's why you'll often find me sans supplements when I'm out of town it makes traveling a bit easier, and it's a perfect time to give your body a rest from supplementation.
As for forms of chromium, although chromium picolinate is certainly a decent option, the general consensus is that the best form of mineral supplement is an amino acid chelate. That simply means the mineral has been attached to an amino acid to facilitate absorption.
For that reason, I typically get my supplemental chromium from BIOTEST Elitepro Minerals.
Speaking of old's cool, let's talk vanadium another mineral with an important role in optimizing glucose tolerance (2).
I still recall the first time I took vanadium back in the early 90's. At the time, there was quite the buzz surrounding the vanadium and its ability to produce massive, skin-stretching pumps. Extreme skepticism was my first reaction, but I must admit I was surprisingly impressed.
Without changing anything else, after a few days of supplementing with vanadyl sulfate I noticed better pumps in the gym, and so did my guinea pig training partner. It was as if my muscles were storing more glycogen, like I'd eaten more carbs.
As I later learned the science behind this, I realized that I probably was storing more muscle glycogen as a result of taking vanadium, due to an improvement in my insulin sensitivity.
I must say, however, that I never felt the almost sudden increase in my training pump again when I supplemented with vanadium. In hindsight, this makes perfect sense, and explains why some people swore by vanadium while others didn't really notice or "feel" anything.
If you have a vanadium deficiency, especially a severe one, you're likely to notice the positive effects that come from supplementing with the mineral. On the other hand, if you're not deficient in vanadium, or at least not significantly so, then you're not likely to notice much, if anything.
When I first took vanadium it's safe to say I was quite deficient. So after suddenly correcting the deficiency, I literally felt the results.
Considering I've never again let years go by without taking supplemental vanadium again, I'm not as likely to "feel" it working which is actually a good thing.
As with many supplements like vitamin C or vitamin D, for example we know they're beneficial even though we don't literally "feel" them working. I believe this to be the case for vanadium.
Personally, I generally consume ~ 60-100 mcg/day in the form of chelated vanadium via 4-7 caps of Elitepro Minerals. That dose, combined with fairly regular supplement holidays, seems to be conservative enough to avoid the potential for toxicity, yet enough to maintain good insulin sensitivity.
If you're like me, finding out that cinnamon has a rather potent glucose management effect (3) is a tad anticlimactic. "Hmmm...that's neat," is the type of reaction I'm talking about.
But pretend for a moment that you heard that a brand new supplement called CGM1029 helps partition nutrients toward skeletal muscle and away from adipose storage.
Now, that's more interesting!
Just because something isn't new, scarce, and sold by a pharmaceutical company doesn't mean we shouldn't get excited about it, or at least pay attention to it. Let's not let the "boring" nature of cinnamon get in the way of realizing its tremendously beneficial effects.
Although I wouldn't disagree with your logic if you decided to take cinnamon capsules, when I consume plain 'ol cinnamon, I prefer to do it the old fashioned way in my oatmeal and with other foods.
(Surprisingly, cinnamon on top of meatloaf is really good. I know, it sounds really odd, but don't knock it till you try it.)
Considering cinnamon isn't a metal, I don't feel it's as crucial to "cycle" it. But I'd always lean toward moderation, when in doubt.
4. Alpha Lipoic Acid
Alpha Lipoic Acid or ALA not to be confused with the omega-3 fatty acid alpha linolenic acid is a neat nutrient, indeed.
Not only does it assist in maintaining (or improving) insulin sensitivity, but it also acts as a potent antioxidant. I'd say it's pretty darn close to being a true supplement superhero.
But if you read studies on ALA (aka thioctic acid), you'll find that some of the studies point to a more neutral effect, as opposed to the incredibly beneficial effects other studies seem to show. Well, it turns out that of the two naturally occurring isomers (r & l ALA), the r seems to be the beneficial one (4).
For that reason, if you're going to supplement with ALA, I recommend going with r-ALA, which is what I do.
Note: As my (and science in general's) understanding of nutrition evolves, I'm increasingly trying to take advantage of nutrient synergy and using less single, isolated ingredients.
As with cinnamon, I'm not really concerned about taking too much r-ALA or taking it too often, but I still take breaks from it to err on the side of caution.
5. Cyanidin 3-Glucoside
If ALA is almost a supplement superhero, then Cyanidin 3-Glucoside is the real deal.
And Cyanidin 3-Glucoside (a.k.a. C3G) is about as cutting-edge as it gets nothing old school about this supplement!
Cyanidin 3-Glucoside (Cyanidin bound to glucose) is a specific type of anthocyanin that appears to be the most significant in terms of physiological effects. Anthocyanins give certain fruits and berries their rich, dark color. Although that role isn't all that exciting for us, its physiological effects are.
For starters, C3G appears to have anti-carcinogenic properties (6). Although avoiding cancer may not be one of your resolutions for 2013, I think we'd both agree that anything that might help us stay healthy is a bonus.
Here's where things get really neat C3G has rather potent antioxidant and anti-inflammatory effects.
Alone, that's just another neat "health" benefit, but C3G has an anti-inflammatory effect on fat cells. This is great, because inflamed fat cells tend to send faulty signals, which unfortunately is horrible for body composition.
By repairing the inflammation and faulty signaling, overall glucose tolerance (and insulin sensitivity) are dramatically improved, much like the prescription drug Metformin.
I've been aware of the mounting research support for the positive benefits of C3G for quite some time, but it's the feedback I've heard that's really impressed me.
For example, a guy I know who took C3G had his blood work done and went from a fasting blood glucose of 117, which is arguably considered pre-diabetic, down to a normal and healthy fasting glucose level of 77 after taking C3G for six weeks. That's incredible!
Although as lifters we're primarily interested in insulin sensitivity for the sake of physique enhancement, the same things that help prevent or treat type II diabetes will typically help improve body composition as well. This is why so many of the nutritional strategies that work for type II diabetics also work for physique athletes.
The strongest and most effective form of C3G available is BIOTEST's Indigo-3G.
6. Carb Management
One often-overlooked strategy of improving insulin sensitivity is manipulating your carb intake.
In short, pounding your body with an abundance of carbs day in and day out, especially high GI carbs, can desensitize your body to carbohydrates. And it does this through a reduction in insulin sensitivity.
Revisiting our bouncer analogy, eating lots of high GI carbs on a regular basis while wanting to improve your insulin sensitivity would be like sleeping with the bouncer's girlfriend and expecting him to let you in the club for free it ain't gonna happen!
Therefore, even if your goal is to gain muscle mass, consider implementing periods of low-carb dieting. It's a strategy I've used with great success, so much so that it's part of my standard operating procedure.
For many reasons, I'm a big fan of cyclical type diets macro-cycling I call it. One of those reasons is that implementing a low-carb diet can re-sensitize your body to carbs (5). Then, when you go back to eating more carbs, your body is more likely to store them as glycogen as opposed to shuttling them off to be stored as adipose tissue.
Even if you don't macro-cycle your diet, at least opt for reasonable amounts of lower GI carbs in all your meals, with the possible exception of your post-workout meal. This will reduce your average daily insulin output and, over time, help improve or at least maintain your insulin sensitivity.
Bonus Training Tip
The focus of this article is nutritional strategies to improve insulin sensitivity, but there's also a training tip that's worth sharing.
I don't know that it's been "proven" through research, but I believe that high volume, glycogen-depleting training can, over time, improve insulin sensitivity. Let me explain.
We do know, through research, that training with high volume can increase glycogen storage capabilities. So let's say you can normally store 350 grams of muscle glycogen (which is about right).
After a few weeks of training with higher volume, which depletes muscle glycogen, your muscles will develop a better ability to store muscle glycogen maybe as much as 400 grams of glucose as glycogen.
This adaptation makes perfect sense, as it prepares our body to better face that high-volume training stimulus again. It also makes sense that our body would simultaneously develop a better ability to properly use glucose (carbs) by way of improved insulin sensitivity.
And since research has shown that resistance training improves insulin sensitivity through multiple mechanisms, it's not a huge stretch to think that, within reason, higher-volume training may offer more of these benefits.
So, although I'm definitely a fan or advocate of high-intensity, low-volume type training programs, I doubt they'll improve your insulin sensitivity as much as possible.
For this reason, I'd occasionally recommend implementing some reasonably high-volume work into your training. For example, stick with sets of 10-20 reps and do four to five sets of four to five exercises per body part.
Yeah, that's a lot of volume, but that's what it takes to adequately deplete muscle glycogen and prepare for the subsequent increase in glycogen storage. As long as you don't take many (if any) of those sets to failure, you should be able to avoid overtraining, assuming you don't implement this strategy for more than about 8 weeks at a time.
If you try it, let me know what you think. But I suspect that if you increase your training volume up to ~ 20 sets per body part and make sure to consume copious carbs, you'll notice that you feel fuller and more pumped after a few weeks, yet without any increase in body fat.
And this effect will be more pronounced if you've been doing a rather low volume of training.
Optimizing insulin sensitivity is definitely something worth investigating. It'll not only benefit you in terms of looking better, but also in health and longevity as well.
Controlling the type and amount of carbs you consume is just sound health advice, but whether you choose to cycle in an insulin-friendly supplement here and there is up to you.
Either way, I hope you've enjoyed and benefitted from this info and now have some actionable steps that you can implement to begin improving your insulin sensitivity.
1. Diabetes & Metabolism. 2000, 26, 22-27
2. J Clin Endo & Metabolism. 2001 Mar;86(3):1410-1717
3. Diabetes, Obesity, & Metabolism. Dec 2009; Vol11, issue 12, 1100-1113
4. AJP - Endo July 1, 1997 vol. 273 no. 1 E185-E191
5. J Am Coll Nutr. 2004 Apr;23(2):177-84
6. J Biol Chem. 2006 Jun 23;281(25):17359-68. Epub 2006 Apr 17.