So often in the fitness community, we’re told to avoid cheap carbs and simple sugars like white bread, candy, cookies, cake, and soda for a couple of reasons.
- They’re calorically dense and nutrient-poor
- They spike insulin levels
- They raise blood sugar levels
- They promote fat storage
- They lead to energy crashes
- They are easy to overeat and derail your diet
It’s easy to see why so many coaches, trainers, and nutritionists steer athletes away from high carb/high sugar foods, and while it’s true that the vast majority of the time you want to avoid these foods, there is a time when it’s more or less “ok” to have some of the quintessential “dirty” foods like candy, pizza, Chinese takeout or fried food -- post-workout.
The post-workout window is those select few hours immediately following your workout where your muscles are starving for energy, desperately seeking nutrients to repair, rebuild, and grow the muscle tissue that you just worked so hard to train in your workout.
That’s why the post-workout time period is so often called the anabolic window. Your body is primed to take whatever you throw at it and use it for recovery and growth. But, what is it about the anabolic window that makes your body work differently than other times of the day. Why is this brief window of opportunity the ideal time to consume high carb/high sugar foods?
It has to do with the most anabolic hormone in your body -- insulin.
What is Insulin?
No doubt you were thrown for a loop when we said that the most anabolic hormone in the body is insulin. You were probably thinking it was something along the lines of testosterone, human growth hormone, or insulin-like growth factor-1 (IGF-1). Make no mistake, those hormones are incredibly anabolic, but it’s insulin that’s the real star of muscle growth and fat loss.
Insulin is “peptide hormone” that is secreted by the β cells of the pancreatic islets of Langerhans, which is a fancy way of stating that insulin is a protein made in the pancreas.<1> The primary function of insulin, as you probably know, is to regulate blood sugar (glucose) levels in the body by transporting glucose from the bloodstream and into muscle cells or fat cells for storage. But that’s not insulin does, it also is primarily known for regulating blood glucose levels by facilitating glucose uptake into your cells, but insulin also <2>:
- Regulates carbohydrate, protein, and lipid metabolism
- Increases the rate of amino acid delivery into tissues (including muscles)
- Reduces glycogen breakdown
- Decreases lipolysis (breakdown of stored fat) in adipose tissue
- Encourages cell division and growth (via mitogenesis)
- Reduces the rate of fatty acid oxidation (fat burning) in muscle and liver
- Increases protein synthesis in muscle (i.e. builds muscle), as well as adipose tissue and many others
- Decreases the rate of protein breakdown in muscle (stops catabolism)
As you can see, insulin plays a vital role not only in muscle growth and repair but also fat burning and fat storage.
And therein lies the quagmire with insulin -- it stores nutrients, period. It does not discriminate between where it stores those nutrients. Insulin is just as likely to store excess blood glucose in muscles as it is adipose tissue (fat cells). Insulin doesn’t really care where it stores the glucose, it’s job is to regulate blood sugar levels and keep them at a safe level. Just because you’d prefer insulin to store all those carbs in your muscles doesn’t mean it’s going to comply. Its job is to keep blood sugar levels from reaching critical status.
Now, some individuals have better genetics than others, and their body’s will preferentially stores more of those sugars in muscle than they will fat. Aside from winning the genetic lottery, this individuals also have superb insulin sensitivity.
What is Insulin Sensitivity?
Insulin sensitivity essentially describes how “efficient” your body is when it’s faced with an increase in blood glucose. In an otherwise healthy, lean individual, they secrete small amounts of insulin to deal with the rise in blood sugar. However, if you have poor insulin sensitivity, also known as insulin resistant, your body secretes large amounts of insulin to deal with the increased blood glucose levels.
With insulin resistance also comes less fat burning, brain and pancreatic cells are exposed to higher levels of blood sugar for longer periods of time (which can be toxic), and muscle protein synthesis falls off dramatically. Suffice it to say, you do not want to be insulin resistant, especially if you’re looking to maintain a lean, muscular physique.
What causes insulin resistance?
A few things, including lack of exercise, excess consumption of simple sugars, as well as several other things. Insulin resistance is a tell-tale warning sign of health complications in the future including obesity, type 2 diabetes, high blood pressure, heart disease, heart failure, and even cancer.
Having poor insulin sensitivity also means you’re more likely to store fat when trying to gain size and strength, as opposed to those excess calories going to pure muscle building. Basically, you want to avoid being insulin resistant at all costs and want to do everything in your power to maximize insulin sensitivity.
Fortunately, there are several things you can do right now to improve insulin sensitivity. Just because you were born with poor genetics doesn’t mean you’re forever stuck with poor insulin sensitivity. By manipulating insulin and taking advantage of it, we can ensure that those tasty carbs we consume post workout go towards muscle growth, not fat storage
How to Improve Insulin Sensitivity
As we noted up top, when insulin levels rise, fat burning stops and energy storage starts. Right here, you can see one of the first “hacks” to improving insulin sensitivity -- what you eat and when you eat it.
By consuming the majority of your carbohydrates before, during, and after training, you’ll force your body to use them for energy production during training and for glycogen replenishment and muscle repair and growth following training. No other time is your body more primed to deal with a surge of carb and sugar-laden food than post workout.
During training, glycogen stores become depleted and insulin sensitivity skyrockets. This improves carbohydrate storage via two different means. Intense exercise, such as weightlifting, not only heightens insulin-dependent glucose uptake into skeletal muscle but also non-insulin dependent glucose uptake, meaning glucose absorption by your muscles without the actions of insulin! <3>
In other words, if there ever was a time for you to crush some serious carbs, it's definitely post workout. Your muscles have been broken, bloodied, and beaten from the workout, glycogen levels are low, and they’re hungry…
That means you need to feed them carbohydrates. They’re begging for them. Carbohydrates are the preferred form of energy for the body during high-intensity exercise, and the quickest way to replenish those depleted glycogen stores is by eating carbs, the simpler the better. This ensures faster digestion, which leads to faster uptake by your muscles, and ultimately quicker glycogen storage and recovery (and less soreness).
Now, that means for the rest of the day, when insulin sensitivity isn’t as high and muscles are not depleted of glycogen, you want to avoid huge spikes in insulin, as well as high carb-low fiber meals. Meals farther away from exercise should be full of fiber (i.e. vegetables), higher in fat and protein. These factors help reduce the glycemic load of your meal, which limits the amount of insulin the body has to release to deal with rising glucose levels in the blood, thereby allowing for more fat burning and less fat storage.
Aside from exercise, here are a few other “hacks” you can use in your daily life to improve insulin sensitivity, so if you do have the occasional cheat meal outside of the post-workout window, you’re not going to store (as much) fat:
High-Intensity Interval Training (HIIT)
A muscle cell that is full of glycogen is technically insulin resistant as it has no more “room” to store glucose (as glycogen), which means the glucose-insulin is carrying is probably going to be stored as fat.
However, performing an exercise that burns glycogen, leaves your muscles empty and increases their insulin sensitivity. There’s no better way to burn through glycogen than with high-intensity interval training (HIIT). <4>
Options for HIIT training include sprints, prowler pushes, bodyweight circuits, or concept2 rower. These forms of exercise burn through glycogen like you wouldn’t believe and if you know you’re going to be having a carb-heavy meal later in the day, but it’s technically an “off day” from lifting, do a quick HIIT session to burn off some glycogen and get the body primed to put those tasty carbs to work.
If you already get 7-9 hours of sleep each night, you’re already doing one of the best things possible for optimizing insulin sensitivity. Getting even more sleep isn’t going to significantly enhance your insulin sensitivity. However, if you’re not getting adequate sleep each night, you might want to start doing so. Research shows that even a single night of disrupted sleep can impair insulin sensitivity! <5>
Aside from insulin, disrupted sleep also raises cortisol levels and decreases testosterone levels, which further hurts muscle growth and encourages fat storage. Basically, if you’re not getting enough quality sleep each night, start doing so...NOW!
Reduce stress levels
Similar to sleep disruption, stress can also wreak havoc on your hormone levels, particularly cortisol and insulin. Stress increases cortisol levels and lowers insulin sensitivity, <6> which is a double whammy for increased fat storage and less muscle growth.
Training in a fasted state can improve insulin sensitivity, as your body is forced to run on its energy stores rather than food you may have ingested as part of your pre-workout nutrition. Research notes that training while fasted increased insulin sensitivity more so than the group consuming a high carb meal prior to exercise. What’s really interesting is that these effects also occurred even though subjects at a “standard American diet” (i.e. high fat, high carb) the rest of the day. <7>
Sprinkle Cinnamon on your Food
Cinnamon is a delicious spice that adds warmth and excitement to any dish, including baked sugary treats like cookies and cakes. It’s also effective for combating insulin resistance induced from sleep loss. <8>
Other pungent spices, such as garlic and ginger, also improve insulin sensitivity, so don’t be afraid to experiment with new recipes and cuisines to enhance glucose disposal in the body and broaden your culinary horizons.
Sprinkling a dash of vinegar on your appetizer prior to a high carb meal, say on a salad prior to a dinner full of pasta, might be an easy way to improve insulin sensitivity, as research documents better glucose tolerance in type 2 diabetics following consumption of vinegar prior to high-carb meals. <9>
Insulin resistance is often the result of excess energy consumption (i.e. overeating). Losing fat increases energy removal from the body, which improves insulin sensitivity, especially if the fat loss comes from belly fat. <10>
Consuming tea, whether it be green tea, black tea, or Pu-Erh tea, has been shown to improve insulin resistance. <11,12> If you are going to consume tea, make sure to not load it up with a bunch of sugar though, as that will negate the insulin-sensitizing benefits of tea consumption.
Now, this is by no means a complete list of ways to improve insulin sensitivity, but they are some of the most convenient ones you can easily work into your daily life.
The bottom line is that carbohydrates aren’t always the enemy, and they’re certainly not bad for you. As with everything in life, “timing is everything.”
If you’re craving some sugary, fast-digesting carbs, just make sure to get in a tough workout beforehand, and that way, you can put those tasty carbs towards building muscle and not storing fat. To help you make the most of your workout and really burn through that muscle glycogen, there’s Steel Pump™.
Steel Pump™ is a scientifically-formulated pre-workout specifically designed to enhance your performance during training. With Steel Pump, you’ll have greater energy, focus, and stamina to push harder in your workouts, burning more glycogen and calories than ever before. After your workout, you’ll be ready to tackle those sugary carbs head on and get the most benefit from them!
- Wilcox G. Insulin and Insulin Resistance. Clinical Biochemist Reviews. 2005;26(2):19-39.
- Dimitriadis, G., Mitrou, P., Lambadiari, V., Maratou, E., & Raptis, S. A. (2011). Insulin effects in muscle and adipose tissue. Diabetes Research and Clinical Practice, 93 Suppl 1, S52-9. http://doi.org/10.1016/S0168-8227(11)70014-6
- Hayashi T, Wojtaszewski JF, Goodyear LJ. Exercise regulation of glucose transport in skeletal muscle. Am J Physiol. 1997;273(6 Pt 1):E1039-51.
- Boutcher SH. High-Intensity Intermittent Exercise and Fat Loss. Journal of Obesity. 2011;2011:868305. doi:10.1155/2011/868305.
- Donga E, van Dijk M, van Dijk JG, et al. A single night of partial sleep deprivation induces insulin resistance in multiple metabolic pathways in healthy subjects. J Clin Endocrinol Metab. 2010;95(6):2963-2968. doi:10.1210/jc.2009-2430
- Li L, Li X, Zhou W, Messina JL. Acute Psychological Stress Results in the Rapid Development of Insulin Resistance. The Journal of endocrinology. 2013;217(2):175-184. doi:10.1530/JOE-12-0559.
- Van Proeyen K, Szlufcik K, Nielens H, et al. Training in the fasted state improves glucose tolerance during fat-rich diet. The Journal of Physiology. 2010;588(Pt 21):4289-4302. doi:10.1113/jphysiol.2010.196493.
- Jitomir J, Willoughby DS. Cassia cinnamon for the attenuation of glucose intolerance and insulin resistance resulting from sleep loss. J Med Food. 2009;12(3):467-472. doi:10.1089/jmf.2008.0128
- Johnston CS, Kim CM, Buller AJ. Vinegar Improves Insulin Sensitivity to a High-Carbohydrate Meal in Subjects With Insulin Resistance or Type 2 Diabetes. Diabetes Care. 2004;27(1):281 LP-282.
- Goodpaster BH, Kelley DE, Wing RR, Meier A, Thaete FL. Effects of weight loss on regional fat distribution and insulin sensitivity in obesity. Diabetes. 1999;48(4):839-847.
- Mozaffari-Khosravi H, Ahadi Z, Fallah Tafti M. The Effect of Green Tea versus Sour Tea on Insulin Resistance, Lipids Profiles and Oxidative Stress in Patients with Type 2 Diabetes Mellitus: A Randomized Clinical Trial. Iranian Journal of Medical Sciences. 2014;39(5):424-432.
- Du W, Peng S-M, Liu Z, Shi L, Tan L-F, Zou X-Q. Hypoglycemic effect of the water extract of Pu-erh tea. J Agric Food Chem. 2012;60(40):10126-10132. doi:10.1021/jf302426w