Q: If you had to pick one thing that often prevents someone from getting lean, fit, and healthy, what would you say it is?
A: I'd have to say too little sleep. Most people fail to realize that getting enough quality sleep (7-9 hours per night) sets the stage for everything else. A good night’s sleep not only gives your body and brain the chance to recover, but it also assists in balancing your hormone levels. This is especially true for the following four hormones:
- Cortisol: The "stress hormone" that has been linked to weight gain when levels are elevated
- Growth hormone: An anabolic hormone (one that promotes muscle growth and the growth of other complex living tissue in the body) that is essential for fat loss (Learn more about how growth hormone works here)
- Leptin: An appetite-suppressing hormone released by the fat cells
- Ghrelin: An appetite-stimulating hormone released by the stomach
There are two main types of sleep: rapid eye movement (REM) sleep and non-rapid eye movement (NREM) sleep, which can be further divided into four sub-stages. A typical night's sleep consists of 75 percent NREM sleep and 25 percent REM sleep. Let’s take a closer look at the different stages:
Wake: This cycle occurs from the moment you fall asleep until you wake up. It's basically the amount of time that you are awake when you should be sleeping. Your time in the wake cycle would be considered part of your "disrupted sleep."
Light: This phase of sleep makes up the majority of an average person's night, about 40 to 45 percent. Also known as stage 2 sleep, the benefits of this phase include increased motor function, concentration, and alertness. When you take a “power nap,” you're primarily reaping the benefits of stage 2 sleep.
Deep: Deep sleep (stages 3 and 4) occurs prior to REM sleep and is primarily linked to mental and physical restoration—which is why, like REM, the time spent in the deep cycle is part of your "restorative sleep." During the deep stages of NREM sleep, the body repairs and regenerates tissues, builds bone and muscle, and appears to strengthen the immune system. It is also during this stage that the body releases growth hormone, which aids in cell growth and regeneration.
REM Sleep: The REM sleep phase usually occurs about 90 minutes after sleep onset, following deep sleep. REM sleep is vital to your overall mood, mental health, and your ability to learn and retain knowledge. It has also been linked to better memory processing, boosting creativity, and helping us deal with emotions and learning complex tasks.
To maximize the overall quality of your sleep, you need to get adequate amounts of both deep and REM sleep every night.
More and more new research supports the importance of sleep as a key component of a well-designed weight loss (or as I like to say, “fat loss”) program, along with diet and exercise. A recent study published in the Canadian Medical Association Journal found that people who slept for longer and had a higher quality of sleep were more likely to become slimmer while on a diet. What's more, the Canadian Obesity Network now includes adequate sleep in its new set of obesity management tools for physicians.
The bottom line: If you want to get lean and fit, make sure you are getting enough quality sleep.