Should you trade sleep for sweat?

If you’re like me, you probably like knowing the reason behind everything. Many of us see rest as a weakness or a waste of time, and, not going to lie, part of me likes being that way, makes me feel more productive in some way. But I can’t pretend that I never feel overwhelmed or exhausted sometimes. So, this week’s newsletter explores the psychology and biology behind rest, and why sleeping may actually make you stronger and better equipped in your quest to do everything.

Before looking at why we need sleep, let’s look at how the body regulates it first.

Our sleep is controlled by two interacting biological processes. The first is the circadian rhythm, an internal cycle lasting approximately 24 hours that helps determine when we feel awake and when we become sleepy. The second is the homeostatic process, which creates an increasing pressure to sleep the longer we remain awake.

Together, these systems influence the timing and intensity of our sleep, but they don’t fully explain why sleep is necessary.

Now there’s 3 main explanations behind the importance of sleeping. First there’s the :

Biological adaptation

From an evolutionary perspective, studies show that sleep may have helped organisms survive by conserving energy and keeping them inactive during periods when moving around would have been dangerous or inefficient.

For example, an animal that could not see well at night would not gain anything from trying to hunt in the dark. So staying inactive at night would conserve its energy, reduce its exposure to predators and leave it better prepared to hunt for food during the day. Over time, natural selection could have favoured those sleep patterns, matching the environment of each different species.

The timing of this sleep is partly regulated by our circadian rhythm, an internal cycle lasting approximately 24 hours. Its main control centre is the suprachiasmatic nucleus, a tiny structure in the brain that receives information about light through the eyes. Light signals help the brain determine whether it is day or night and they also help coordinate changes in alertness, body temperature and hormone production. When night/darkness approaches, the circadian system promotes the release of melatonin from the pineal gland, which helps the body prepare for sleep, and cortisol to help you wake up.

This is why bright light from a phone late at night can interfere with sleep. It doesn’t completely confuse the brain, but it can suppress or delay melatonin production, making it harder to feel sleepy at night.

PS : Did you know that the word circadian comes from latin word “circa” which means “around” and “dies” which means “day”.

The second explanation is :

Physiological restauration

Even though you are sleeping, your brain and your body stay active. When we sleep, the body performs its usual maintenance such as : restoring energy, repairing tissues, regulating hormones, and clearing some metabolic waster that accumulated in the brain during the day.

Deep sleep, also known as slow-wave sleep, plays a very important role in physical recovery. During this stage, heart rate and blood pressure decrease, the body’s energy demands are lower, and growth hormone is released. This hormone supports the repair and growth of muscles, bones and other tissues, which is very important after training.

Sleep is also essential for the brain. It helps with attention, reaction time and memory consolidation, which in other words, is the process through which newly learned information becomes more stable and easier to retrieve later.

For performance, the important idea is that training and studying create a demand, but part of the adaptation happens after. Without good sleep, the muscles may recover less effectively, and the brain may struggle with concentration, reaction time and remembering what was learned. So despite the work that happens during the day, sleep is part of what allows that work to produce results.

The third explanation is :

Memory support

Learning doesn’t end when you stop studying or practising. While you sleep, your brain continues processing and stabilizing what you learned during the day.

The information you first absorb while awake goes through a process called memory consolidation during sleep. This means that a new memory becomes more stable and is gradually integrated with knowledge you already have. Later, this can make the information easier to retrieve and use.

Different stages of sleep have shown to support memory in different ways. Slow-wave sleep, also known as deep sleep, is more present during the first half of the night. It is especially associated with consolidating declarative memories, including facts, knowledge and events. During this stage, the brain may reactivate patterns connected to recent learning, helping stabilize the information.

REM sleep occurs throughout the night but becomes longer and more abundant during its second half. It contributes to emotional memory, skill learning integrating more complex information. REM sleep may help the brain connect new information with existing knowledge, recognize patterns and understand the bigger picture.

This is especially relevant to performance. Sleep can help a student retain what she studied, but it can also help an athlete stabilize a movement or skill practised during training. Practice gives the brain new information, sleep helps organize and preserve it.

A note on REM sleep: REM stands for rapid eye movement, referring to the quick movements of the eyes behind closed eyelids. During this stage, brain activity becomes more similar to wakefulness, and vivid dreams are common. “Most voluntary muscles also become temporarily inhibited, which helps prevent the body from physically acting out those dreams.”

Key Takeaways

Rest is part of the work

• While you sleep, your body repairs the tissues you challenged, your brain stabilizes what you learned, and your biological systems prepare you to perform again. Training creates the stimulus, studying introduces the information, and sleep gives the body and brain time to adapt. It’s all very simple and a good system if you learn to work with it properly.
• So, if you’re trying to become stronger, learn more or take on several goals at once, sleeping less is not necessarily giving you more time. It may simply leave you with less energy, weaker concentration and less ability to benefit from the work you already completed.