Sleep deprivation is a major health issue facing many people today. Unfortunately, most don’t seem to care.
We’ve all undoubtedly heard the phrase “You snooze, you lose”; the idea being that, if you’re sleeping, you’re missing out on success, opportunities, general tomfoolery, etc.
Well, whoever coined that phrase is a blithering idiot, to put it nicely.
Sleep is important…like super important. Lack of sleep has been link to everything from obesity to early death. Staying out until bar close doesn’t sound all that important now does it?
You may think that diet and exercise are the biggest drivers of progress, whether you are trying to lose fat, build muscle, or just get healthier. But you know what the biggest driver of a successful diet and exercise program is?
If you guessed sleep, you get a gold star for the day.
Sleep affects everything. Your hunger, hormones, ability to train and recover effectively are all directly related to the quality of your sleep.
If you take a detailed look at the effects sleep deprivation has on your body, it gets scary.
And that’s just what we’re going to in today’s article
Before we get into the effects not sleeping has on you, we first need to know what constitutes “a good nights sleep”.
Like most fitness-y things, this is highly individual. Some people may be able to function on 6 hours, while others need 10. The general research consensus is that most adults need between 7-9 hours of sleep per night.
If you wake up tired in the morning, finding it hard to get out of bed, or hit the snooze alarm multiply times, you need more sleep. If however, you wake up ready to jump out of bed and don’t need four cups of coffee to function, you got enough sleep.
For me personally, I find right around 8 hours to be my sweet spot. Not only do I wake up feeling more refreshed, but I’m also mentally sharper and more productive.
Now, I’m not saying there’s anything wrong with staying up later occasionally. However, if you’re under-sleeping four or more nights per week, late-night partying or TV should NOT be your first priority.
The three hormones affected most by sleep deprivation are leptin, ghrelin, and cortisol.
Leptin is mainly determined by the amount of fat mass you have. The higher your body fat percentage, the higher your leptin levels. This is good when it comes to fat loss because the higher your leptin levels, the easier it is to lose fat.
The problem is that dieting and weight loss naturally reduce leptin. This is one of the reasons why the longer you diet, and the more you lose, the harder it becomes to lose fat. And guess what else lowers leptin levels? That’s right, lack of sleep.
Sleep deprivation also increases the body’s production of ghrelin. This is the hormone responsible for making you feel hungry. The more ghrelin that’s produced, the hungrier you feel. This is why people report feeling an increase in hunger the day after a poor night’s sleep. By decreasing leptin and increasing ghrelin, the body makes it damn near impossible to lose fat.
A lack of sleep also increases the body’s production of cortisol. And while increased cortisol is not a bad thing, chronically elevated levels (like those associated with sleep deprivation) are.
Cortisol is frequently associated with fat gain because it activates the reward center in your brain that makes you crave food. And not the good kind either.
To make things worse, chronically elevated levels of cortisol also prevent muscle protein synthesis, which decreases hypertrophy and actually leads to the body breaking down muscle tissue.
Being sleep deprived also directly hinders the body’s ability to build muscle. Testosterone, the number one hormone when it comes to hypertrophy, is directly related to sleep quality. Studies have shown that decreases in testosterone production of 10% or greater can occur from sleep deprivation.
Growth hormone (GH) production, which helps the body burn fat and build muscle, is also hindered by sleep deprivation. Most of the body’s GH is produced while you’re sleeping, and increased cortisol actually slows GH production. So not only do you produce less GH because you sleep less, but by sleeping less your increased cortisol levels hinder your GH production even further.
While the hormonal environment a lack of sleep creates can make it tough to lose fat, it appears that even if your diet is on point, being sleep deprived can still slow fat loss.
A study published in the Annals of Internal Medicine found that the amount of sleep you get can affect how much fat you actually lose.
The study took 10 overweight individuals and divided them into two groups: one group that slept 8.5 hours per night, and one that slept for 5.5. The study also controlled caloric intake of the participants, limiting them to about 1,500 calories per day.
At the end of the 14-day study both groups lost the same amount of weight. HOWEVER, the group that got 8.5 hours of sleep per night lost half of their weight in fat mass, while the 5.5 hour group lost less than a quarter of their weight in fat. Moreover, the participants in the less sleep group lost more muscle mass, meaning a higher drop in metabolic rate.
So yes, you can drop fat while being sub-optimally rested. But you’re going to have to diet longer, deal with more hunger issues, and experience more damage to your metabolism than you would if you just got more damn sleep.
Sleep loss also hinders your decision-making ability. When you’re sleep impaired, your mental clarity, focus, and willpower is decreased. You’re tired and may often feel like you’re in a fog. This can make it tough to tackle dieting decisions like resisting foods you know you shouldn’t eat, but are craving because of your elevated cortisol levels. It’s a vicious cycle.
Last but certainly not least, sleep deprivation can directly affect your performance in the gym, and your recovery. Not only does less sleep inhibit the body’s ability to build muscle, which helps burn more fat, but it also impairs your performance in and out of the gym.
Being under-slept leads to less energy, less focus, a slowed reaction time, and shortened attention span. All this decreases the intensity and effectiveness of your workouts, and can put you at greater risk for injury.
It also limits the time your body has to recover from physical activity. When we sleep, the body doesn’t need to expand energy on certain processes we need while were awake, so it can use that energy to build and repair muscle. Less sleep means less time your body spends repairing and recovering.
Hopefully by now I’ve convinced you just how important sleep is, not just to achieving your fitness goals, but for your general health as well.
The connection between sleep and obesity is hard to ignore. According to the CDC, over 30% of adults get less than 6 hours of sleep per night, while the obesity rate hovers just slightly higher at 35%. Given those numbers, and all we’ve discussed here today, it’s safe to assume sleep deprivation and weight gain are related.
And considering all the health risks associated with obesity and being overweight, is a few extra hours of sleep really that big of a price to pay?
I’ll answer for you…NO!
So now that we know why sleep is important, how do we maximize our sleep to make sure we’re getting the most benefits possible?
Come back later in the week for Part 2 of this article, where we’ll discuss tips for getting a good night’s rest.