Let’s talk about insulin sensitivity.
Insulin is a hormone that’s secreted by your pancreas. Insulin has many vital roles within the body, but the one it’s probably best known for is storage. This is a bit of a double edged sword, as, on one hand, this can be highly useful, as insulin helps to shuttle nutrients to muscle cells, where they’re stored and used to aid rest, repair and recovery following training.
In that respect, high levels of insulin are good, as they improve your rate of muscle growth and performance. It can also have a beneficial impact on energy levels, as another of insulin’s main roles is to store any carbohydrate you eat in the muscle cells and liver. Full stores here = lots of energy for optimal performance.
However, this can also be a downside. Once your carbohydrate stores are full, insulin needs to shuttle these carbs somewhere else. And that “somewhere else” ends up being fat tissue. Ergo, high insulin levels = potential for fat gain.
Additionally, if your insulin levels are constantly high, you run the risk of becoming pre-diabetic, which can eventually morph into full-blown diabetes.
Importance of managing insulin levels
Not only that, but constantly rising and falling levels of insulin make you feel tired, lethargic, irritable and hungry.
Insulin sensitivity refers to how your body generally manages insulin. A high level of insulin sensitivity is good, as it means your body needs to produce and release less insulin when you eat carbohydrate. Whereas low levels of insulin sensitivity (also known as insulin resistance) has the opposite effect – your body produces huge amounts of insulin when only a little should be needed.
While that may be a little “science-y,” it’s important to understand the basics of insulin before we look at the effect that your sleep has on it.
Just remember that in an ideal world, insulin will be lower the majority of the time if you want to stay lean, fit and healthy.
Sleep to improve body composition
We all know more or less why sleep is just so important.
For one thing, sleep is the time when your body recuperates and recovers – lose sleep, your performance will be down, and you could well lose muscle mass and compromise hormone production. Plus, when you’re tired, you don’t concentrate as well, and this can lead to hunger pangs, cravings and over-eating. That’s all common knowledge.
Something that isn’t quite so well known however, is how a lack of sleep has a huge detrimental effect on insulin sensitivity.
A 2012 study from “The Annals of Internal Medicine” concluded that –
“Sleep restriction results in an insulin-resistant state in human adipocytes. Sleep may be an important regulator of energy metabolism in peripheral tissues.” (1)
What this essentially means, is that when you lose sleep, your insulin sensitivity goes right down, to the point where it can have a direct impact on your fat loss. Adipocytes are your fat cells, so if these are resistance to insulin, it means your body has to produce more insulin to do the same job, and as we learned from the introduction to this article – that’s never a good thing!
“Just One Night Can’t Hurt … Can It?”
In a word – Yes!
Check out the results of this study from the “Journal of Endocrinology and Metabolism” –
“Partial sleep deprivation during only a single night induces insulin resistance in multiple metabolic pathways in healthy subjects. This physiological observation may be of relevance for variations in glucoregulation in patients with type 1 and type 2 diabetes.” (2)
In layman’s terms –
The metabolic pathways are how efficiently your body digests and utilizes different fuel sources. If you’re insulin resistant, your body simply can’t do its job as well, and carbohydrates aren’t used easily, which once again results in more being laid down as fat, rather than being stored for energy, or deposited in muscle tissue.
The Issue with Shift Work
If you’re sitting there thinking –
“Well, I don’t sleep regular hours, but I do make sure I get plenty, so I’m okay” … wait just a second.
According to a study from a 2014 edition of the “Journal of the American Diabetes Association” –
“Circadian misalignment as occurs in shift work may increase diabetes risk and inflammation, independently of sleep loss.” (3) So even if you do get a fair few hours between the sheets, if you’re constantly changing your sleeping patterns, you’re putting yourself at serious risk of fat gain. Inflammation is another risk factor often associated with obesity too, so rising inflammation levels may be another nail in your weight loss coffin.
What’s a Guy to Do?
Above all – don’t ever overlook the importance of sleep. Most people need around 6 to 9 hours. Too little can definitely impact insulin sensitivity, which will lead to you storing more fat, not performing as well in the gym, and potentially increasing hunger and cravings too. Experiment to find what works best for you.
Don’t neglect sleep quality either.
To guarantee a full, restful night’s sleep, follow these guidelines –
- No technology for 1 hour before bed.
- Read for 30 minutes prior to sleep.
- Make your room as dark as possible.
- Cut caffeine a few hours out, and drink herbal teas instead.
- Take a warm bath or shower if it helps you relax.
- Turn off all cell phones, TVs and appliances in your room.
Place as much of an importance on sleep as you do on your training, diet and supplementation, and you’ll see your results skyrocket.