The Insulin Advantage
How to Bulk and Cut on the Same Day
Forget the outdated idea of months-long "bulking" and "cutting" phases that the newbies love to talk about. Instead, bulk and cut throughout the day, maximizing muscle gains while controlling body fat.
How? By manipulating insulin.
Depending on your background, you probably think of insulin as either the anabolic Holy Grail or the natural enemy of fat loss. Which is it? Let's find out.
Insulin is Like a Woman
It's human nature to label something as good or bad, but this myopic outlook often does us more harm than good. You'd think we would've learned this lesson in the 80s when we erroneously demonized dietary fat, but alas, we humans tend to be slow learners.
Those passionate about fat loss label insulin an evil bastard of a hormone that's making us chubby by inhibiting fat burning and promoting fat storage. On the other hand, those focusing on muscle building label insulin's anabolic and anti-catabolic actions as nothing short of magical.
How can a simple hormone be a fat boy's nemesis anda skinny boy's secret weapon?
The truth is, insulin is like a woman: sometimes she loves you, sometimes she hates you. But the good news is that unlike a woman, we can accurately predict how insulin will act.
Know Your Opponent
Insulin is an anabolic hormone. In fact, it's even more anabolic than growth hormone. The problem is, it's indiscriminately anabolic and doesn't care whether it helps promote the building of muscle or the accumulation of fat.
But you can't blame insulin. After all, it's just a hormone doing its job. And its primary job is to maintain safe and steady blood glucose levels of around 80-100mg/dl.
So when blood glucose levels rise above 100, insulin is secreted by the pancreas. Then, ever-so-helpful insulin "picks up" the extra glucose out of the blood and takes it to a storage depot for safe keeping.
There are three different storage depots for this extra glucose: muscle glycogen, liver glycogen, or adipose tissue. Of course we prefer storage in the former rather than the latter, but the reality is that insulin doesn't care. It'll simply do what it's programmed to do.
So let's look at exactly what insulin is programmed to do.
1. Insulin Builds Muscle
Insulin stimulates protein synthesis by directing ribosomes to make more protein. If that sentence didn't give you muscle-building fans at least partial wood, then I need to explain.
Muscle is made of protein. Protein is manufactured by ribosomes. Ribosomes are turned on by insulin. Allow me to quote Guyton and Hall's Textbook of Medical Physiology:
"In some unexplained way, insulin 'turns on' the ribosomal machinery. In the absence of insulin, the ribosomes simply stop working, almost as if insulin operates an 'on-off' mechanism."
So does this mean that insulin "helps" build muscle? No, it means that insulin is required to build muscle.
2. Insulin Inhibits Catabolism of Protein
Insulin inhibits the breakdown of muscle. Although it may not seem as exciting, the anti-catabolic nature of insulin is every bit as important as its anabolic nature.
Anyone with financial intelligence will tell you it doesn't matter how much money you make; it only matters how much money you keep. The same goes for muscle.
Every day, your body synthesizes some protein and breaks down some protein. Whether or not you gain muscle mass over time is like a physiological math game. To build muscle, you must synthesize more protein than you catabolize. It's like keeping more money without making more money.
3. Insulin Transports Amino Acids into Muscle Cells
Insulin actively transports certain amino acids directly into the muscle cells. Guess which amino acids get this special treatment? That's right – BCAA! Branched-chained amino acids are personally escorted into muscle cells by insulin, a very good thing if you want to build muscle!
4. Insulin Increases Activity of Glycogen Synthase
Insulin increases the activity of the enzymes (i.e. glycogen synthase) which stimulate glycogen formation. This is very important as it helps ensure the storage of glucose in muscle cells, thereby improving performance and recovery.
In more immediately tangible terms, muscle glycogen formation results in much fuller, denser-looking muscle.
So far so good, but what about the other side of the coin?
1. Insulin Inhibits Hormone-Sensitive Lipase
Insulin inhibits an enzyme called hormone-sensitive lipase, which is responsible for breaking down adipose tissue. That's obviously not good, because if you can't break down stored fat (triglycerides) and turn it into a form that can be burned (free fatty acids), you're not going to get leaner.
2. Insulin Decreases Utilization of Fat
Insulin decreases utilization of fat for energy, and instead promotes the burning of carbohydrates for energy. To put that another way, insulin "spares fat."
Although that's not good for our body composition, it makes perfect sense when you recall that insulin's main function is to get rid of extra glucose in the blood. And insulin will accomplish this by both storing more carbs and burning more carbs.
3. Insulin Increases Fatty Acid Synthesis
Insulin increases fatty acid synthesis in the liver, which is step one in the process of gaining body fat. But, this is dependent upon the availability of excess carbs – an amount above what is immediately burned or stored as glycogen.
4. Insulin Activates Lipoprotein Lipase
Insulin activates an enzyme called lipoprotein lipase. If you know a little medical terminology, this may sound good at first. After all, lipase is an enzyme that breaks down fat, so why wouldn't you want to increase it?
Recall that we just discussed how insulin increases fatty acid synthesis in the liver. Once those extra fatty acids are converted to triglycerides, they're picked up by lipoproteins (i.e. VLDL), dumped into the bloodstream, and told to go find a home.
The cool thing so far is that triglycerides can't be absorbed into adipose cells. So even though you may have ample triglycerides in your blood, you're not actually getting fatter... yet. That's where lipoprotein lipase comes in.
Once activated by insulin, lipoprotein lipase breaks down these triglycerides into absorbable fatty acids which are quickly and easily soaked up, converted back into triglycerides, and stored by adipose cells.
5. Insulin Promotes Glucose Transport into Fat Cells
Insulin promotes the transport of glucose across fat cell membranes and into the fat cells. As you can imagine, the story of excess glucose in fat cells doesn't have a happy ending. Guyton and Hall summarize:
"All aspects of fat breakdown and use for providing energy are greatly enhanced in the absence of insulin."
Notice they said fat breakdown and fat burning are enhanced in the absence of insulin.
Solving the Insulin Riddle
Insulin is simply an anabolic transport hormone that does its job. It's not good or bad. It doesn't care whether you gain fat or gain muscle. All it cares about is keeping blood glucose in the normal range. When blood glucose gets high, insulin will be secreted and will work quickly to restore normal serum glucose levels.
It's not up to insulin to secrete itself at the right time. It's up to YOU to stimulate insulin release at the right time, and in the right amount if you're really good. And there's a way to do just that.
First, decide where on the fat loss/muscle gain continuum you lie:
I Only Want Muscle Gain!
If your primary goal is to gain muscle, then you want high levels of insulin throughout the day.
You especially want high-insulin levels after training to take advantage of the fact that at that time, the muscle cell membrane is extra permeable to insulin and whatever it is carrying (i.e. glucose, BCAA).
I Only Want Fat Loss!
If your goal is strictly fat loss, then you want lower levels of insulin throughout the day, on average.
At first thought, some people think that having low insulin levels all day every day is the way to lose fat. But unless your idea of exercise is mall walking, you need a more intelligent strategy.
Even if you couldn't care less about gaining muscle mass, it's still important to initiate some insulin secretion post-workout. This will stop the training-induced catabolism as well as shuttle glucose and amino acids into the muscle cells. Otherwise you'll find yourself losing valuable muscle and therefore hampering the metabolic machinery that burns fat!
You don't want to look skinny-fat, do you? Well, that's exactly what you'll look like unless you routinely give your muscles much-needed carbs.
I Want to Gain Muscle and Lose Fat!
Now here's a goal everyone can relate to: gaining muscle and losing fat.
Sadly, most of us believed others when they told us that it wasn't possible to gain lean muscle while losing body fat. Conventional wisdom still says that one must alternate between "bulking" and "cutting" cycles to achieve more muscle mass with less body fat. But this so-called wisdom isn't so wise after all.
When blood glucose is high, insulin is secreted and glucose is stored in muscle glycogen or liver glycogen. When blood glucose is low, insulin secretion is diminished and fat becomes the body's primary fuel source.
Insulin is like a switch that controls from moment to moment whether we're burning fat or building muscle. It doesn't take a whole day for this change to occur. In fact, it only takes minutes!
What this means is that you can plan your day to have periods of time focused on building muscle and periods of time focused on burning fat. And you can manipulate the length of these periods to alter the rate at which you gain muscle and lose fat.
Want to gain muscle faster? Increase the amount of insulin you secrete. This is especially beneficial to do immediately after resistance training for many reasons, one of which is because insulin will not convert glucose to fat if it can first store it as glycogen. And after an intense weight-training session, both muscle and liver glycogen are depleted and ready to soak up serious glucose. So, don't be shy with the carbs at this time.
For even faster muscle gain you should also boost insulin levels another time or two throughout the day. You could accomplish this with a couple more carb-containing meals. You could either have one of these prior to training and one after, or both after training (and after your post-workout drink).
Then, in order to cover the fat loss part of this equation, keep insulin levels low during the remainder of the day.
Flip the Switch
Whether you're promoting muscle gain or maximizing fat loss, insulin is the switch you need to learn to flip: "on" for muscle gains, "off" for fat loss.
Whichever you choose, remember that the switch doesn't have to stay flipped up or down for months at a time. Choose to manipulate insulin on a daily basis and you can reap the benefits while avoiding the drawbacks.