Chapter 1-5: Sleep, Stress, Exercise, and Energy (Vocabulary)

Sleep, Dream Recall, and Sleep Architecture

The brain is constantly active: it governs conscious thoughts and also regulates subconscious processes (e.g., heart beating) and dreams during sleep.
REM sleep is described as a deep/active sleep stage where dreaming is common. The question raised: why do people wake up during REM or remember dreams if REM is deep? The point is that REM is a distinct stage within sleep; dream recall varies and waking during REM can lead to remembering dreams.
Dream recall frequency:
- Not everyone remembers multiple dreams every night; in fact, you don’t typically remember a dream every night.
- Memory of dreams depends on whether you wake during or shortly after REM, and how the sleep cycles unfold.
Sleep cycles and depth:
- Your brain and body shift through sleep cycles. Repeated cycles occur and can be more or less thorough depending on factors like tiredness and stress.
- The idea presented is that as you tire your brain and body, you go through sleep cycles more readily and thoroughly; regular cognitive effort (learning) and physical activity interact with how you experience sleep.

Stressors come in various forms (physical, emotional, cognitive).
Brain perception of stress depends on how it moves through sleep cycles; the same stressor may be processed differently depending on the stage and state of sleep.
Examples of stressors discussed:
- Everyday physical stressors (e.g., running from car to dorm in the rain; wet shoes; forgetting an umbrella).
- Emotional stressors (e.g., the experience of a loved one passing).
- Cognitive stressors (e.g., exams).
There is no universal answer to how a particular stressor is perceived; it varies per person and depends on how it interacts with sleep stages and cycles.
There are ongoing newer studies examining how repeated stresses interact with sleep patterns and recovery.

Deep sleep is described as highly important because it is the stage where the body undergoes repair processes.
The claim: deep sleep plays a central role in physical restoration, which underpins overall sleep quality and daytime function.

Over-the-counter sleep aids can alter what is considered “good sleep” by affecting the natural progression through sleep cycles (light sleep → deep sleep → REM).
Benadryl (diphenhydramine) is cited as an example of a drug that can alter sleep quality or the architecture of sleep stages.
Caffeine and stimulants: heavy caffeine use disrupts sleep; personal habit example includes needing to stop tea by early afternoon to avoid sleep disruption.
Medication interactions (e.g., antidepressants, antibiotics like Z-packs, steroids) can influence sleep, sleep architecture, and daytime functioning; these effects vary by individual and context.
Practical takeaway: sleep quality hinges on maintaining the natural sequence and integrity of light sleep, deep sleep, and REM, and on minimizing factors that disrupt these cycles (stimulants, certain medications, inappropriate sleep aids).

Exercise is linked to better sleep quality when done regularly, but the relationship is nuanced.
The definition of “exercise” varies; not all movement counts equally.
- Walking all day may count for some, but true exercise typically implies certain intensity or duration that meaningfully elevates heart rate.
- An objective criterion mentioned is that heart rate must reach a certain level to count as aerobic exercise; there are also anaerobic processes used when energy is insufficient or during high-intensity efforts.
Aerobic vs. anaerobic processes:
- Aerobic exercise requires oxygen and supports energy production over longer durations.
- Anaerobic processes occur when energy demand exceeds oxygen supply; these are used during short, high-intensity efforts.
There is a connection between regular exercise and being more fit, but “exercise” can vary in how it affects individuals; the impact on sleep depends on the type, intensity, and timing of activity.
A reference to a graph suggests that the course will illustrate differences between aerobic and anaerobic energy pathways and how they relate to sleep and recovery.

Energy is produced in the form of ATP; when thinking about energy, ATP should come to mind first.
Nutrients used for ATP production include monomers such as glucose and fatty acids.
Pathways discussed:
- These nutrients are used in processes that require oxygen (oxidative metabolism) and in processes that generate ATP.
- There is an emphasis on the role of oxygen in aerobic metabolism as a key component of sustained energy production.
A schematic understanding (conceptual):
- Glucose and fatty acids are substrates that, in the presence of oxygen, are metabolized to produce ATP, CO₂, and H₂O.
- The presence of oxygen enables the aerobic pathway to efficiently generate ATP for longer-duration muscle activity and body processes.

Pizza is cited as an example of a mixed-energy source: it contains carbohydrates, fats, and sometimes proteins.
Takeaway: a single food item can supply multiple macronutrients that contribute to energy production and muscle function, illustrating how the body draws on various nutrients depending on activity and metabolic state.
The idea of macronutrient balance is linked to how different muscle groups rely on glucose, fats, and proteins during different types of activity.

Lab three is introduced as an upcoming activity to examine the differences between proteins, carbohydrates, and fats.
Practical constraint: there will be no eating in the lab, but students will test or observe differences between organic nutrients to understand how macronutrients differ.
The exercise will emphasize how the nutrient content of foods relates to energy production and muscle use, depending on the muscle group involved.
The concluding note connects understanding nutrition to practical exploration of which nutrients are utilized by different muscle groups during activity.

Sleep quality and cognitive load (learning) interact with physical activity to shape sleep architecture and dream recall.
Stress perception is dynamic and moderated by sleep stage, cycles, and individual physiology; stressors can be physical, emotional, or cognitive (e.g., exams).
Deep sleep supports body repair and restoration; disruptions to deep sleep can impact daytime functioning and recovery.
Substances (caffeine, medications) influence sleep architecture and quality; mindful management of intake and medication timing can improve sleep outcomes.
Regular, appropriately intense exercise supports sleep quality and overall fitness; the classification of exercise (aerobic vs. anaerobic) matters for energy metabolism and endurance.
Energy to power muscle activity and bodily processes comes from ATP generated from glucose and fatty acids, with oxygen playing a central role in aerobic metabolism.
Nutritional content of foods (carbohydrates, fats, proteins) influences energy availability; mixed foods like pizza illustrate how macronutrients contribute to energy reserves and muscle performance.
Laboratory exploration of macronutrients will deepen understanding of how different nutrients are utilized by muscles during activity, linking theory to practical observation.