What initiates cortisol production in the adrenal gland?
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The hypothalamus in the brain.
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What initiates cortisol production in the adrenal gland?
The hypothalamus in the brain.
How many calories do you burn when climbing 11 floors of stairs?
19.7 calories.
How many calories do you burn if you park your car a mile away from work and walk?
80 calories.
What role does sleep play in memory reprocessing?
Sleep is an important part of memory reprocessing, with brain activity patterns corresponding to practiced movements being repeated at night.
How does stress affect the testosterone-to-cortisol ratio (TC ratio)?
Stress elevates cortisol, which antagonizes testosterone, predictably lowering the TC ratio.
What is the difference between psychological stress and biological stress?
Psychological stress may not suppress neuromuscular recovery unless it is associated with a biological stress response and suppression of the parasympathetic nervous system.
How many REM phases does a person above the age of 2 generally experience each night?
4 - 6 REM phases.
What happens to the amount of time spent in stage N3 (deep sleep) as you get older?
It generally decreases.
What is the medical term for brain wave recording?
Electroencephalogram (EEG).
How does high psychological stress affect recovery after strength training?
High psychological stress can double the time needed to recover from workouts.
How does subjective sleep quality correlate with objective sleep quality?
Subjective sleep quality overall correlates quite well with objective sleep quality in healthy people.
What is the key to successfully increasing your activity level?
Making lifestyle changes rather than spending days making trivial decisions.
What is a good reference for healthy sleep?
Healthy sleep entails falling asleep within 30 minutes.
What is the medical term for eye movement recording?
Electrooculogram (EOG).
What is the medical term for muscle activity recording?
Electromyogram (EMG).
What does a polysomnogram display?
Waves in multiple rows, with each distinct wave corresponding to markers like EEG, EOG, EMG, and ECG.
How do afternoon workouts compare to morning workouts in terms of sleep duration?
Some research finds that afternoon workouts may improve sleep duration compared to morning workouts, but most research finds the timing of exercise trivial for sleep quality.
What is a common outcome of virtually every lifestyle intervention to improve sleep quality?
It improves athletic performance and recovery.
What characterizes Cushing’s syndrome?
Chronically high cortisol levels.
What happens in the motor cortex after practicing movements like squats?
At night, the motor cortex practices the squat movements again.
What should a good training program take into account for stressed trainees?
A good training program should take into account the stress experienced by the individual, potentially lowering training frequency or volume.
What is stress-induced analgesia?
A phenomenon where sensitivity to pain from physical stressors decreases.
How does body fat percentage relate to sleep requirements?
Sleep requirements seem to increase as body fat percentage decreases, possibly due to a lower tolerance for stress.
What are the characteristics of REM sleep?
Muscular tone is reduced to zero, heart rate, breathing rate, blood pressure, and cerebral blood flow all rise, and dreams occur.
What is polysomnography?
Polysomnography is a method of quantifying sleep stages using sensors to measure small electrical currents emitted by mammals and birds.
What are the potential long-term effects of chronic sleep restriction?
You may suffer permanent brain damage and increased lifetime risk of neural diseases and memory impairments.
How many extra calories can an afternoon of standing office work burn compared to staying seated?
174 kcal extra.
What is the effect of sleeping ~6 hours instead of 8 hours a day for just 4 days on energy intake?
It can increase your ad libitum energy intake by 20%.
How many stages of non-REM sleep are there?
Three stages (N1 - N3).
Why is it still useful to ask clients how stressed they feel?
Because psychological stress is very real in the mind of the person experiencing it and can affect their fitness lifestyle.
What is the old golden rule of sleep quality?
Waking up without an alarm every day around the same time feeling fully refreshed.
How does stress affect the healing time of various pathologies?
Stress considerably impairs the healing time of various pathologies, including simple wounds.
Is the brain active during sleep?
Yes, the brain is quite active during sleep and its activity changes systematically across different stages of sleep.
What physiological changes occur during the stress-response?
Increased heart and breathing rates, mobilization of glucose, fatty acids, and amino acids, blood vessel constriction, and blood directed away from the skin.
What are the effects of sleep deprivation on nutrient partitioning?
It causes hugely unfavorable alterations, reducing rates of myofibrillar protein synthesis.
What is a simple strategy to ensure you drink enough water throughout the day?
Keep a calorie-free beverage on your desk and make sure it's empty at certain times of day, like before meals or before going to the gym.
Why doesn't comfort eating help much in combating chronic stress?
The pleasurable sensation of eating is brief, and food does not provide a significant biochemical reward compared to important life events.
How can fixing your sleep affect your body composition over the course of a year?
Fixing your sleep can help you gain pounds of muscle and lose pounds of fat without exercise or dieting.
What is the impact of a night without sleep on testosterone production?
A night without sleep can impair testosterone production by 24%.
Why do athletes spend a larger proportion of total sleep in a slow-wave state?
Because their physical recovery requirements are higher.
What is the sequence of sleep stages during a full night's sleep?
We go through 5 cycles of the 3 non-REM sleep stages, each ending in a REM phase.
What is a simple and practical option for measuring sleep quality?
Subjective sleep quality is a simple and practical option.
What ratio can be used to monitor the training status of athletes in relation to stress?
The testosterone-to-cortisol ratio (TC ratio).
What happens when the body is in fight-or-flight mode all the time?
Being in fight-or-flight mode all the time doesn't leave enough room for rest-and-digest mode, slowing down immune and digestive systems and suppressing reproduction, growth, and repair.
What effect does chronic stress have on energy expenditure?
Chronic stress can reduce energy expenditure.
What happens to synaptic strength during wakefulness?
There is a net increase in synaptic strength during wakefulness due to plastic changes needed to process information.
Why is a consistent meal frequency beneficial for health, body composition, and mental wellbeing?
A consistent meal frequency helps maintain a stable biorhythm, which is beneficial for health, body composition, and mental wellbeing.
How can you tell if you have slept enough regardless of sleep duration?
If you wake up naturally at the same time every day and feel completely refreshed.
What are the benefits of using a standing desk or treadmill desk?
They increase activity level without disrupting work quality or productivity, and they don't increase appetite.
Why might you not achieve a major increase in energy expenditure with a standing desk?
Because we are intuitively inclined to lower our spontaneous physical activity level after periods of higher activity.
What is 'eustress'?
'Eustress' is a form of stress that can be healthy for the body, helping it stay strong and active.
Why is polysomnography not commonly used outside of a laboratory?
Most people don't have access to polysomnography outside of a laboratory.
How does sleep affect learning and memory?
Tasks and skills are better learned and memorized if you sleep in between sessions.
What is the stress-response?
An ancient survival mechanism characterized by the release of cortisol, adrenalin, and other hormones from the adrenal gland, putting the body in fight-or-flight mode.
What happens to synaptic strength during sleep?
During sleep, synaptic strength is downscaled to maintain homeostasis.
How many sleep cycles does a typical night's sleep consist of?
5 sleep cycles, each approximately 90 minutes long.
What is the percentage increase in energy expenditure when performing desk work standing instead of seated?
11.5% increase.
What is considered a sign of good sleep efficiency?
Having a sleep efficiency of at least 85%.
What is the impact of common levels of sleep deprivation on body composition?
Common levels of sleep deprivation can significantly impair gains, leading to increased fat gain, especially in the abdominal area, and promoting an unhealthier body fat distribution.
What is the relationship between additional waking time and cognitive functioning?
There is a nearly linear dose-response relationship where each hour of additional sleep debt decreases brain functioning almost as much as the hour before.
What is the relationship between sleep and the immune system?
Sleep is closely linked to the functioning of our immune system and is an important modulator of endocrine function, including hormone production.
Where does cortisol production occur?
In the adrenal gland.
How can psychological stress interfere with fitness goals?
Psychological stress can interfere with dietary adherence, training motivation, and sleep quality, which can in turn interfere with muscular recovery.
What is wakefulness?
Wakefulness describes the daily recurring state in which an organism engages in coherent cognitive and behavioral responses to the external world.
What is synaptic homeostasis?
Synaptic homeostasis is the process by which sleep allows the brain to reestablish synaptic and cellular balance.
What is the medical term for heart rate recording?
Electrocardiogram (ECG).
What are the potential health risks associated with consistently sleeping more than 9 hours?
It may be associated with depression and boredom.
What is the advisable amount of sleep per night for strength trainees?
9 hours per night, after correcting sleep debt.
What is the effect of a little stress on diet adherence?
A little stress is good for diet adherence because it suppresses appetite.
What does polysomnography measure?
It measures small electrical currents emitted by the body and analyzes four markers corresponding to different levels of activity for each sleep stage.
How much can a treadmill desk increase energy expenditure per hour?
100-150 kcal per hour.
What is the Pittsburgh Sleep Quality Index (PSQI) used for?
To measure sleep quality in great detail.
How does extreme sleep deprivation affect growth hormone production?
Growth hormone production may decrease with extreme sleep deprivation.
Why is it generally not worth purchasing and wearing a sleep quality device for most people?
Because everyone should try to optimize their sleep quality with low-effort strategies regardless of what a sleep tracker says.
What should you do if you are not waking up feeling fully refreshed?
Prioritize getting more sleeping time and implement additional sleep optimization strategies.
How is sleep defined under normal conditions?
Sleep is defined as a reversible behavioral state of perceptual disengagement from and unresponsiveness to the environment.
What is an example of an implementation intention for commuting to work?
If it rains, I go to work by car. Otherwise, I go by bicycle.
Why is sitting for prolonged periods harmful even if you exercise regularly?
The time spent seated is an independent predictor of dozens of health complications.
Why is sleep deprivation considered more of a hindrance to strength training than chronic stress?
Because it makes you more vulnerable to stress and has negative effects on almost every system in your body.
How does intense training affect sleep requirements?
Sleep requirements increase as a result of intense training.
How effective are naps for counteracting fatigue?
Naps are highly effective for counteracting physical and mental fatigue acutely.
When is it generally best to limit your naps to?
Late morning or early afternoon.
How can catching up on sleep debt for 2 weeks affect energy intake?
It can reduce your ad libitum energy intake by several hundred Calories.
How does sleeping 5 hours a night affect testosterone production?
It can decrease testosterone production by ~13%.
What is the significance of stage N3 (slow-wave sleep)?
Stage N3 is associated with increases in growth hormone production and is important for physical restoration.
What are the mechanisms of action by which increased stress and reduced sleep quality can harm someone's body composition goals?
Increased stress and reduced sleep quality can lead to hormonal imbalances, increased fat storage, muscle loss, and impaired recovery.
How can you assess the impact of someone's stress level and sleep quality on their body composition changes?
By monitoring changes in weight, body fat percentage, muscle mass, and overall physical performance, while also considering subjective measures like mood and energy levels.
What strategies can help optimize someone's sleep quality?
Strategies include maintaining a consistent sleep schedule, creating a restful environment, limiting screen time before bed, and managing stress.
What are some high-stress conditions that illustrate the effects of hormonal disruptions?
Burnout and Cushing’s syndrome.
How can you help someone sustainably increase their activity level?
By setting realistic goals, incorporating enjoyable activities, gradually increasing intensity, and providing ongoing support and motivation.
What happens to physical performance in athletes after a few days of insufficient sleep?
Physical performance starts to deteriorate.
What is one tip to increase activity level when working behind a desk?
Make a habit of drinking lots of fluids to prevent prolonged sedentary posture and slightly raise metabolism.
How does strength training affect sleep quality?
Strength training improves sleep quality.
What is the research consensus on sufficient sleep duration for sedentary individuals?
7.5-8 hours per night.
Which nervous system and hormones are responsible for the appetite-suppressing effects of stress?
The sympathetic nervous system and the hormones adrenaline and noradrenaline.
What hormone is responsible for increasing the desire for food during high amounts of stress?
Cortisol, the stress hormone.
Why is REM sleep named as such?
Because during REM sleep, the eyes move in a rapid manner underneath the eyelids corresponding to the content of the dream.
Why might sleep be important for early brain development?
Newborns sleep substantially more hours than adults, and about 50% of their sleep shortly after birth is spent in REM sleep phases, which may play a role in neural development.
What increases more than objective strength or work capacity due to sleep deprivation?
Training distress and perceived effort increase far more.
What are the consequences of living a very stressful life?
You age faster, accumulate oxidative stress, and die sooner.
What is the main issue with psychological life stressors?
Psychological life stressors are often chronic, while the stress-response evolved to be episodic, not chronic.
What techniques can help reduce someone's stress level?
Techniques include practicing mindfulness, engaging in regular physical activity, maintaining a healthy diet, and seeking social support.
What are synapses?
Synapses are the connections between our nerve cells.
What are implementation intentions?
Clear, concrete if-then rules for your life, also known as action triggers.
How can different sleep stages be distinguished in a polysomnogram?
Each sleep stage emits a different frequency and intensity of EEG waves.
How much sleep is recommended for human adults aged 18-60?
7+ hours per night.
What happens during slow-wave sleep (N3)?
Most bodily functions are reduced, heart and breathing rates are reduced, and pupils narrow, signaling a more parasympathetic tone.
Why is routine considered efficient?
Routine is considered efficient because it allows you to forget your diet and not think about what to eat, when to eat, or when to train.
How do women and men differ in their reliance on comfort food to counteract stress?
Women generally rely more on comfort food to counteract unhappiness and stress than men.
Are unhealthy foods more effective than healthy foods in reducing stress?
No, unhealthy foods are not more effective than healthy foods in reducing stress.
How do people typically misjudge their sleep duration?
They overestimate it by about half an hour a day.
How can a stable biorhythm improve overall wellbeing?
A stable biorhythm with fixed meal times, caffeine use, light exposure, and exercise can improve cognitive functioning, physical performance, and overall wellbeing.
Why are naps not a replacement for nighttime sleep?
Unless you nap for a full sleep cycle of ~90 minutes, you won’t enter deep sleep.
What is the effect of sleep deprivation on basal metabolic rate?
Sleep deprivation can cause a 2-8% decrease in basal metabolic rate, often with no change in total energy expenditure despite a generally higher activity level.
How does the body compensate for lack of nighttime growth hormone production during mild sleep deprivation?
The body compensates with increased daytime production.
Why do many people underestimate the impact of sleep?
Because sleep deprivation does not have much negative effect on acute strength levels.
What are the characteristics of N1 sleep stage?
Sleep starts at a 'shallow depth' (N1) and gets deeper over time.
What is a stronger predictor of all-cause mortality than total sleep duration?
Sleep regularity is a stronger predictor of all-cause mortality than total sleep duration.
Is remembering your dreams a sign of good sleep quality?
No, it suggests you spent a relatively large amount of time in REM sleep instead of deep sleep.
How does sleep deprivation affect cortisol production?
Cortisol production generally stays roughly the same but can become more variable.
What is one of the metabolic consequences of sleep deprivation?
Increased insulin resistance, both acutely and chronically.
How does sleep deprivation affect overall wellbeing?
Sleep deprivation decreases wellbeing.
How does sleep change with age in relation to slow-wave sleep?
Older populations show decreasing time spent in a slow-wave state, in line with their reduced physical recovery requirements.
How does sleep deprivation impact exercise performance?
Sleep deprivation impairs exercise performance mainly due to underrecovery and reduced willpower and motivation.
How does sleep deprivation affect systemic inflammation levels?
Sleep deprivation increases systemic inflammation levels.
What are some cognitive effects of sleep deprivation?
Decreased cognitive functioning, including impaired self-control.
How can one compensate for feeling fatigued due to sleep deprivation during exercise?
With willpower and motivation, though recovery afterwards may be an issue.