Acute Sleep Deprivation Skeletal Muscle Protein Synthesis and Hormonal Response
Written by Ben Bunting: BA(Hons), PGCert. Sport & Exercise Nutrition. British Army Physical Training Instructor.
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The effect of acute sleep deprivation on skeletal muscle protein synthesis (MPS) has been a subject of interest for many years.
However, recent findings suggest that the effects of acute sleep deprivation are more complex than originally thought.
This may have important implications for athletes, especially those who are in the high-intensity phase of training.
Insomnia and sleep deprivation
Sleep deprivation is a problem that affects a lot of people. It can cause many symptoms, including mood changes, a decrease in alertness, and a loss of energy. It can also interfere with memory and learning.
In addition, lack of sleep can negatively affect the immune system and cardiovascular system. It can increase the risk of chronic health problems, such as heart disease and obesity.
A person who suffers from sleep deprivation often experiences mood changes, such as depression, anger, and anxiety.
They may have trouble concentrating and judging other people's emotions. They can also be more prone to accidents. They are at a higher risk for car crashes, work injuries, and accidents at the hospital.
Insomnia is a sleep disorder characterized by difficulty falling asleep, staying asleep, or waking up frequently during the night. It is a common sleep disturbance that affects nearly 70 million Americans annually.
Insomnia is a condition that can be either temporary or chronic. Insomnia can occur as a result of physical illness, medications, or psychiatric disorders.
Insomnia can also be caused by stress or a traumatic event. Insomnia can lead to impaired daytime functioning, poor mood, and difficulty performing at work.
If you have been experiencing some of these symptoms, you should see your doctor. Insomnia is associated with heart disease, hypertension, and coronary artery disease.
Insomnia is often associated with depression and anxiety. Insomnia can be an uncomfortable side effect of many medication. Insomnia can also be a result of medical conditions, such as Alzheimer's and Parkinson's diseases.
Insomnia can also be an unwanted side effect of antidepressants, stimulants, and medication to treat high blood pressure, ADHD, and Parkinson's disease.
Having insomnia isn't uncommon, especially if you have a stressful job. It is also more common in women than men. Insomnia is a condition that is a leading cause of death in the U.S. It is also more common among older adults.
Insomnia is a common condition that can be prevented or treated through simple changes in daily habits. One of the best ways to do this is to create a relaxing bedtime routine. Another helpful technique is to avoid taking caffeine and alcohol before going to bed.
Depending on the cause of your insomnia, there are a number of different treatments. Cognitive therapy involves replacing dysfunctional beliefs with healthy ones. It can help reduce anxiety and improve your sleep.
The measurement of MPS
Muscle protein synthesis, or MPS, is a process of adding new proteins to skeletal muscle tissue, which increases muscle mass. It also has a role in repairing damaged muscle proteins. It is the reason why a well-rounded training regimen is essential to enhance muscle growth.
There are several ways of measuring muscle protein synthesis, the most common being fractional synthetic rate (FSR).
A Fractional synthetic rate of 0.04 %/h means that 0.04% of total muscle is synthesized every hour. This translates into a net increase in muscle size in a matter of weeks.
The best measurement involves a highly enriched intrinsically labeled protein and an accurate measurement device. This combination allows you to measure your MPS in a controlled environment that minimizes any potential biases or pitfalls.
There are plenty of other measurement techniques to choose from, such as de novo muscle protein synthesis, a measurement of amino acids in blood, and a measure of cellular protein turnover.
However, these are complicated and require a high degree of expertise to interpret. These techniques are also prone to errors and can lead you down the wrong path if not done properly.
The most important metric to measure is the one that reveals how quickly your muscle gains in size after training.
Interestingly, this metric is not entirely dependent on how long you train, but rather on your adherence to a program.
Nevertheless, a good measure of the effects of protein intake on your muscular growth should be the number of grams of protein consumed per hour, as it is an important factor in optimizing your muscular anabolism.
Pre-sleep protein ingestion stimulates muscle protein synthesis
Pre-sleep protein ingestion increases muscle protein synthesis rates during overnight sleep and supports skeletal muscle adaptation to resistance-type exercise training.
It is particularly effective when ingested in the immediate post-exercise period and may facilitate enhanced recovery.
Interestingly, it does not appear to reduce appetite during the night. In addition, it does not affect glucose or fat metabolism during the night.
Another study, conducted in younger adults, reported a positive association between pre-sleep protein ingestion and overnight muscle protein synthesis.
In addition, the study showed that 40 grams of protein ingestion before sleep resulted in an increase in overnight protein balance. In older adults, the effect of pre-sleep protein ingestion was even greater.
In both groups, overnight muscle protein synthesis rates were higher than those observed during the day.
The researchers noted that the results of this study provide strong evidence that a combination of pre-sleep protein and resistance-type exercise is beneficial in enhancing the recovery of muscle proteins.
Further research has shown that the consumption of whey or casein proteins prior to bed may improve strength gains.
It is important to note that the amino acid content of these proteins is of particular interest. For example, leucine has been shown to closely correlate with brain waves, which can be a marker of muscle synthesis.
In fact, whey proteins have been linked to higher muscle protein synthesis rates.
One study reported that the addition of casein to the diet of eight men prior to bed was associated with a larger increase in muscle protein synthesis than ingesting 20 grams of casein with 1.5 grams of leucine.
This may be because the protein was digested more effectively during the night. In addition, this study also found that the respiratory quotient was unchanged in the casein group.
This is in line with previous findings that pre-sleep protein ingestion may help augment muscle recovery.
Post-exercise protein ingestion inhibits muscle protein breakdown rates
If you have performed a significant amount of resistance-type exercise and are looking to increase your muscle mass and strength, pre-sleep ingestion of protein sources may be the dietary strategy for you.
Research suggests that this strategy is not only effective in augmenting muscle mass, but also promotes the reconditioning of muscle during sleep.
There are three main meals in the typical day and each represents a unique opportunity to stimulate muscle protein synthesis.
Typically, athletes consume between 1.2 and 1.6 g of protein per kilogram of body weight every day. For optimal benefits, an even distribution of total protein intake is required, as well as a moderate insulin concentration. This is the only way to maximize muscle protein synthesis.
A supplementary meal such as a protein-rich snack in the evening does not further reduce protein breakdown, but increases post-absorptive muscle protein synthesis.
In a study of the post-exercise protein synthesis phenomenon, the largest increase in muscle protein synthesis was induced by the largest increase in protein ingestion.
In this study, 40 g of casein protein was given to the volunteers immediately before bed.
This protein was effectively digested throughout the night, which resulted in a more favorable protein balance than the placebo drink.
The authors concluded that this increase in post-exercise muscle protein synthesis is due to the increased availability of amino acids during overnight recovery.
In a study of overnight recovery from an ultra-endurance race, a mixture of carbohydrate and protein was ingested as a single drink.
The combination of carbohydrate and protein increased the overnight muscle protein synthesis rate (MPS) but not the overnight muscle protein synthesis rate (MPS) as seen from a conventional protein-only approach.
A study of intragastric protein ingestion after a whole-body resistance exercise found that this increased post-exercise muscle protein synthesis in elderly men.
This increase was also accompanied by an increase in the plasma amino acid enrichment of the sample. Although the benefits of protein ingestion are numerous, the timing of protein intake during the day is not yet well understood.
The authors propose that an even distribution of total protein intake at different times of the day is the most effective means to increase post-exercise muscle protein synthesis.
There are a number of factors that influence overnight muscle protein synthesis rates. These include amino acid composition, metabolism, and the timing of protein ingestion.
These factors are especially important in the context of ageing. A high concentration of leucine in the bloodstream, for example, closely correlates with brain waves.
In addition, a rapid amino acid supply to the muscles is associated with faster muscle recovery. However, it is not enough to maximize overnight MPS, as MPS rates are not maintained over prolonged periods of sleep.
Sleep Deprivation and MPS
For the past few decades, researchers have been able to observe and quantify a variety of physiological changes in the body. For example, in response to trauma or trauma-induced sleep deprivation, skeletal muscle protein synthesis is reduced by about 40%.
While the physiology of this effect remains unclear, studies have found that presleep ingestion of protein can augment overnight muscle protein synthesis. This may help preserve muscle mass in a senescent population.
In the context of this study, a comparison of presleep and placebo protein ingestion was made with the goal of gaining insight into the mechanism of this beneficial effect.
The results showed that protein supplementation was associated with an extended positivenegative net protein balance (NPBAL).
Although the findings did not translate to increased muscle growth, it was noted that the NPBAL did not vary with the protein dose.
In addition, the use of stable isotopes to maximize muscle protein synthesis was a worthy endeavor, especially given the growing body of evidence that skeletal muscle plays a vital role in maintaining the metabolic health of the body.
This role is complemented by a growing body of evidence indicating that a diet enriched in protein has a positive impact on muscular strength and endurance, both at rest and during activity.
In fact, several studies have shown that a diet rich in lean protein is a more effective means of increasing muscle mass in the elderly than in the young.
Aside from preserving muscle mass, a higher intake of protein also helps maintain metabolic fitness during an energy deficit.
A 2021 study found that one night of complete sleep deprivation resulted in a significant reduction in post-prandial muscle protein synthesis (MPS) in young adults.
Additionally, this study also found that sleep deprivation significantly reduced markers of protein synthesis pathways. The researchers hypothesized that chronic sleep restriction may negatively impact muscle protein synthesis through changes in hormone secretion.
Moreover, they proposed that the hormonal environment may play a role in the pathophysiology of muscle protein breakdown.
Ultimately, the results of these studies suggest that protein ingestion before sleep may be effective in promoting the recovery of muscle protein synthesis, and may contribute to the preservation of muscle mass and function in the elderly.
The Effect of Acute Sleep Deprivation on the Hormonal Environment
Acute sleep deprivation has been shown to disrupt the hormonal balance between anabolic and catabolic hormones in humans. This can lead to a variety of effects on the body.
Balance of anabolic and catabolic hormones is disrupted
A study in humans comparing the effects of a single night of sleep deprivation to an otherwise ordinary night of recuperation found that total sleep deprivation is a stumbling block to human performance and well-being.
During the course of a lifetime, the ramifications of poor sleep are far-reaching. Among the negative effects are impaired cognitive performance, increased risk of obesity and diabetes, and worsened mood and quality of life.
Fortunately, the problem is preventable. Acute sleep deprivation has been proven to reduce testosterone levels and inhibit the nocturnal release of growth hormones. This is why the topic of sleep and sleep deprivation has become a hot topic in the world of sports medicine.
One study suggests that a lack of quality sleep may increase the risk of developing chronic health conditions such as diabetes and cardiovascular disease. This, in turn, may sabotage one's ability to enjoy a healthy, active lifestyle.
During the study, blood samples were collected from each participant and analysed. The researchers tested the effects of each night's worth of snooze on testosterone and growth hormone levels.
The results showed that overnight sleep deprivation prompted a 24% drop in total testosterone levels and a 15% increase in the hormone's free-floating FSR.
In addition, this snooze induced decline in testosterone levels was accompanied by a corresponding spike in cortisol levels.
Enhanced susceptibility to CSD
Acute sleep deprivation increases susceptibility to cortical spreading depolarization (CSD), an electrophysiological event that is a common trigger of migraine aura.
Although the underlying mechanism is unclear, studies suggest that it is mediated by inhibition of the Na+/K+ pump ATPase.
In one particular study Sprague-Dawley rats were deprived of sleep for six or twelve hours. The effects of this deprivation on CSD frequency were tested using a general linear model of covariance analysis.
In addition to the increased cortical spreading depolarization frequency, the electrical stimulation threshold was also significantly lower after 12 h of sleep deprivation.
The evoked responses to hinpaw stimulation, whisker stimulation, and forepaw stimulation showed heterogeneous changes in the rats.
In addition, the duration of cumulative CSDs did not change in VLPO-lesioned rats. In wild mice, three-h restraint stress did not affect CSD susceptibility. In FHM1 mutants, females were more susceptible than males.
These findings suggest that female preponderance in migraine is related to gonadal hormones.
In a 133Xe SPECT study, spreading cortical oligemia was associated with CSD. A possible explanation for this oligemia is that oxidative stress compromises the activity of the Na+/K+ pump.
This may lead to a decrease in adenosine influx into the somatosensory cortex and impair the clearance of KCl by cortical astrocytes. In the same study, Ca2+ imaging revealed a facilitated cortical resting state.
Conclusion
Sleep deprivation results in an acute reduction of protein synthesis and degradation in skeletal muscle.
It is also associated with a reduced muscle strength and a poorer exercise performance. These effects may be explained by a hormonal response to the deprivation.
Sleep deprivation affects the major anabolic hormones and catabolic stress hormones. It is thought that the hormonal response to sleep debt affects the balance between protein synthesis and degradation.
These changes result in a decrease in the total synthesis rate and a reduction in the area under the curve of anabolic hormones such as testosterone and growth hormone.
It is believed that testosterone plays a central role in the regulation of muscle protein synthesis.
Some studies suggest that the negative effects of sleep deprivation are more pronounced in men. However, more research is needed to determine how poor sleep affects skeletal muscle.
One study found that a single night of total sleep deprivation results in an 18% decrease in postprandial muscle protein FSR and a 24% decrease in testosterone.
These changes were not associated with an increase in oxidative stress. The decrease in Mhc2 gene expression was not prestated.
The results showed that the increased levels of cortisol following sleep deprivation had a negative effect on the protein synthesis rate of skeletal muscle. It may also contribute to the increased occurrence of protein atrophy.
