I don’t think anyone will argue that sleep is good for you, but despite it’s obvious good, we still seem to live in a society that is constantly sleep deprived. While we know sleep is good for us, what happens when we don’t sleep? The short answer is, a TON. And, it’s all terrible. Keep on reading to check it out.
Effects on Weight Loss
The good news is, you can lose weight! The bad news is, it’s not the weight you want to lose.
A 2010 study measured the weight loss, and body composition of participants who slept for 8.5 hours, and 5.5 hours. The results were substantial.
Both groups had approximately the same caloric deficit, and approximately the same caloric expenditure. The outcome was that both groups lost about 6.6lbs during the study. BUT….
The 8.5 hour group lost about 50/50 fat and lean mass, and the 5.5 hour group lost 20/80 fat and lean mass.
You read that right. 80 PERCENT of the weight the sleep deprived group lost was MUSCLE. I honestly freaked out when I read this and wanted to take a nap. Essentially you lose 2.3x more fat mass with 8.5 hrs. vs. 5.5hrs.
If that’s not enough, check out what else happens to you if you don’t sleep enough.
Impact on Testosterone
I wrote about this in another article about hypertrophy. If you’d like to get the details on the impact on testosterone, and IGF-1, check out that article. Based on the studies listed there, testosterone and IGF-1 are reduced, which help you to build muscle. In addition, a 2015 paper found that:
Day-to-day testosterone levels were significantly decreased by 10 to 15% in young men who underwent just 1 week of sleep restriction to 5 hours per night.
Some of you are now freaking out about your T levels, but some of you may be saying, well, 10% isn’t THAT bad. Well let’s put it in perspective. As you age, your T levels decrease. We all know that horrible eventuality is coming for us. If we apply the 10% decrease to natural decreases in T levels, someone who sleeps only 4-5 hours per night is essentially aging themselves 10 YEARS.
Imagine the amount of muscle you’re hoping to build over the next 10 years before that happens. Well.. good luck with that if you’re not sleeping enough.
When you’re dieting, hunger is something you’re trying to avoid at all costs. Food selection can help with this, which I’ll probably write about in a future article. Sleep deprivation on the other hand, has the opposite effect.
In this study, animals subjected to sleep deprivation for prolonged periods of time increase their food intake substantially. Recent studies in humans have also shown that the levels of hormones that regulate your satiety & fullness are affected as well .
There are two major hormones that have a significant impact on your hunger. Leptin, and Ghrelin.
Leptin is a hormone that essentially tells your body that it isn’t hungry anymore, and Ghrelin is basically the opposite. It tells your body that you don’t have enough food, and should eat.
When we look at sleep loss and the effect on these hormones, we see a decrease in leptin, and an increase in ghrelin. This is exactly the OPPOSITE of what you’d want to see happen when in a calorie deficit. This could lead to excessive caloric intake when food is not needed. The findings also suggest that compliance with a weight-loss diet is negatively impacted due to these negative changes.
I hope you’ve read enough of my articles to already know that prolonged increases in cortisol (stress hormone) is bad for muscle growth, and really life in general.
One of the first effects of sleep loss is an increase in cortisol levels in the early evening. Normally at this time of day, cortisol is rapidly decreasing in order to obtain minimal levels before your normal (if you have a normal, and if not you should) bedtime.
The rate of the decrease of cortisol in the early evening was about 6X slower in subjects who undergo 6 days of sleep restriction compared to subjects who are fully rested. Increases in cortisol levels result in chronic sleep loss, and are likely to increase the risk of insulin resistance, and as a result, obesity and diabetes.
So not only will the increase in cortisol decrease the likelihood that you’ll be building muscle, but you’ll also be more likely to develop diabetes.
Perception of Performance
Ok Cam, but I’m one of those people who only needs 5 hours of sleep.
So this is true, some people have a special gene called DEC2 that allows humans to sleep less, and remain healthy. But how do you really know that you have this? Unless you took a DNA test, you don’t know, and you probably don’t have it.
The issue is that the perception of your own performance is flawed. If you restrict your sleep for a full week, the first 2-3 days you’ll notice a decline in performance and cognitive function. From there, you’ll most likely report that the decline has stopped.
Well, studies have proved that you’re wrong.
You do continue to decline night after night, but your cognitive function has declined enough that to you, it SEEMS like you’re doing ok.
Trust me, you’re not ok.
If you haven’t been convinced yet, let’s start talking about the effect on your lifespan, and risk of death.
There is a global experiment that is performed on 1.6 BILLION people across 70 countries, twice a year. How is this possible?
Daylight savings time.
In the spring, when we lose an hour of sleep, there is a 24% increase in heart attacks the following day. In the fall, when we gain an hour, there is a 21% decrease in heart attacks. There are similar percentages for car crashes and suicide rates.
Sleep is VERY important, and every hour counts.
Your Immune system
Ok, so lack of sleep might kill you, but how does it affect your health day to day? Well you’re immune system won’t be thanking you for lack of sleep.
If you are going to have your sleep restricted to four hours for a single night, you’re going to see a 70% reduction in natural killer cell activity. SEVENTY PERCENT. WHAT???
Researches are now finding links between short sleep and your risk for numerous forms of cancer. Currently the list includes cancer of the bowel, prostate, and breast.
The link between sleep deprivation and cancer is so strong, that the World Health Organization classified any form of nighttime shift work as a probable carcinogen.
How To Get More Sleep
There are a few things that you should be doing in order to ensure your sleep is as good as possible.
- Avoid alcohol late at night, and caffeine at least 6 hours before bed.
- Avoid screens for at least 30 min before bed (2 hours may be best)
- Go to bed and wake up at the same time, every day.
- Keep it cool, around 65 degrees for most people.
- Only use your bed for sleep, and *wink* fun time.
If you wake up at night and can’t fall back asleep, go to a different room and do something else for a while, then come back to bed. This goes along with keeping your bed and even bedroom for sleep.
Sleep is incredibly important. Sleep deprivation can cause a host of issues, all listed below just to scare you a bit more. Some of which I didn’t touch on in this article!
- Muscle loss
- Fat gain
- Increased hunger
- Increased stress
- Decline in cardiovascular health
- Decline in immune performance
- Increased risk of cancer
- Decreased memory
- Decreased cognitive function
- Increased risk of depression & anxiety
If that doesn’t convince you to sleep more, I’m not sure what will. Your body NEEDS sleep, and the only way for you to continue to perform as a human being is to give your body what it needs.