Pre-Sleep Protein - The Apeiron Life Perspective

8 min read

What it is:

Dietary protein is required for every process in the body, as it provides the basic building blocks for life: amino acids. We utilize these proteins to maintain muscle health, break down toxic waste, cell communication, and many other areas. Muscle cells are a particularly critical area. Cardiac muscle keeps our blood flowing, smooth muscle facilitates peristalsis in the intestines, and skeletal muscle allows us to maneuver from A to B.

Long, densely-packed muscle fibers rich in contractile proteins band together to form our skeletal muscles, accounting for ~40% of our body weight. These muscle fibers are continuously broken down and rebuilt. Resistance training is one of the most critical methods of naturally increasing skeletal muscle mass. One way it does this is by inducing muscle fiber hypertrophy via micro-tears in the muscle fibers. In response to these micro-tears, your body repairs and rebuilds the muscle fibers, making them stronger and thicker. This process of muscle repair and growth, known as muscle protein synthesis (MPS), increases muscle mass over time.

Sleep offers an essential window during which these repairs can happen. Yet, our bodies can't reach optimal repair without the correct building blocks. Sufficient protein intake is vital for maximizing repair and muscle growth. We recently discussed the role of meal timing in regulating circadian rhythms, but research shows that protein consumption before bed may offer unique benefits to muscle health.

The purported claims:

Sleep - Essential for muscle growth, repair, and loss of muscle mass
Timing - Some studies show that pre-sleep protein consumption improves muscle mass and next-day recovery
Quantity - 40g of protein pre-sleep may be the optimal amount
Quality - Not all proteins are created equal

What the science says:

Proteins make up a crucial component of the human diet. Current daily recommendations are 56g for males and 46g for females, or about 0.8g per kg per day. However, recent research suggests intake should be much higher and recommend ~1.6-2.2 g/kg depending on the individual. A recent meta-analysis showed that ~1.3g per kg per day benefited those undergoing resistance training.

Quantity of muscle mass is a result of the balance between protein synthesis and protein breakdown. Resistance training creates low levels of damage to the muscles, which undergo repair and hypertrophy, increasing in size if provided with adequate resources. These resources include ingested protein, and sufficient rest.

Sleep offers the deepest, most nourishing source of rest within the 24-hour day and creates an environment in which proteins can repair. Muscle damage creates a localized, acute, inflammatory environment, during which stem cells are activated to rebuild new muscle. We then need to replenish this stem cell pool to allow for future hypertrophy. The localized damage differs from injury and can help prevent future injuries from occurring during training.

It has been well-documented that sleep loss contributes to low levels of systemic inflammation, which increases the risk of many different diseases and disorders in the body, including those associated with the immune system, cardiometabolic function, digestive tract, nervous system, and more. Sleep offers a potent dose of parasympathetic activation, or “rest and digest” mode, which prevents sustained inflammation, including hormone disruption.

Growth hormone is essential for growth and repair. Its release generally coincides with slow wave sleep, though this can change with older age, such as postmenopausally for women. It has been shown that peak growth hormone release is delayed when bedtime is delayed, and total growth hormone secretion is blunted when sleep duration is curtailed. Interestingly, however, a growth hormone deficiency can lead to worse sleep. While this kind of deficiency is generally due to genetics, chronic sleep deprivation may lead to chronic growth hormone suppression, which, in turn, impairs our ability to get back on track with our sleep in a kind of vicious cycle.

Growth hormone is necessary to increase muscle mass, although a whole suite of other hormones are involved too. Testosterone, for example, is a potent regulator of protein synthesis, as well as motivation among both men and women. It has been shown that the greatest percentage increase in testosterone from baseline (rather than absolute values) is associated with an increased likelihood of winning an athletic competition. Testosterone is also associated with power, relevant for those types of exercise where we are not necessarily competing with others. When salivary testosterone was high in a group of menstruating athletes, motivation and neuromuscular power were also higher.

Recent research has focused on the dynamics of testosterone and cortisol, the so-called “stress” hormone. Some studies of competition have found that winners had elevated cortisol compared to losers, while others have found the opposite to be true. Cortisol has been shown to block testosterone’s ability to contribute to motivation and dominance. A short burst of cortisol is a necessary part of the stress response that occurs during many types of exercise, but its rapid decline back to baseline is essential. Testosterone is also crucial for preventing insulin resistance, as shown in a recent clinical trial. It is known that sleep loss increases the risk of developing cardiovascular disease. When transdermal testosterone was administered to young, healthy, sleep-deprived men, they did not develop insulin resistance.

Cortisol exhibits a circadian rhythm, peaking in the morning around the time we wake up, and decreasing steadily over the course of the day. Sleep loss can misalign this rhythm, causing cortisol to surge when we are trying to relax and wind down for the night. In chronic sleep loss, we become more susceptible to chronic stress, and often experience increased cortisol secretion. Given the ways this may disrupt testosterone function, doing our best to get enough sleep at night is essential.

Sleep is also crucial for pain management. Our pain threshold drops when we are sleep deprived. This can lead to lower next-day stamina and greater muscle soreness which can deter us from exercising.

Pre-sleep protein

Several studies have investigated whether protein consumed before bed leads to muscle protein synthesis (MPS), muscle maintenance, and improved next-day performance. These studies have generally focused on supplements and specifically casein versus whey. While more research is needed, such as investigating whole food items, the research points towards ~30-40g before bed may be optimal.

Sleep Improvement

In a study of elite athletes who consumed whey pre-sleep found no significant change in sleep quality or quantity. However, amino acid composition may be a factor in sleep outcomes. Blends containing theanine may promote relaxation and lead to better sleep. In one study, a supplement containing theanine and alpha-s1-casein tryptic hydrolysate led to improved sleep in adults. Alternatively, supplements containing tryptophan, a precursor for melatonin, may also aid sleep.

Muscle Growth

The studies are mixed on whether a dose of protein before sleep will encourage muscle growth. One study found that men in their seventies who consumed 40g of casein before bed had higher protein synthesis. Another trial comparing the consumption of 45g of whey versus 45g of casein among 36 healthy young men resulted in greater mitochondrial and myofibrillar protein synthesis compared to placebo.

Pre-sleep protein may be more beneficial for the non-athlete than those who engage in high levels of physical activity for a living. For example, there was no difference between a placebo supplement, pre-sleep whey, or afternoon whey among young professional cyclists. The researchers noted that these athletes naturally consumed a high-protein diet. Therefore, individuals with low intake levels may benefit most from pre-sleep protein.

Although casein consumption has shown sustained plasma amino acid concentrations overnight, this does not necessarily translate into muscle growth. For example, one study compared whey to a plant-based rice and pea protein supplement consumed before bed and found neither improved muscle growth nor next-day soreness among a sample of 27 middle-aged men.

Approximately 10% of ingested proteins are used to synthesize new skeletal muscle. Roughly 50% are extracted by the abdominal organs (including the liver, pancreas, and gastrointestinal tract), and the rest is used for energy production and neurotransmission. Beyond a protein deficiency, loading the body with protein before bed may not increase the rate of protein synthesis in the muscles beyond a maximum innate capacity.

Most studies look at isolated supplements or protein blends rather than whole food items. This may significantly impact the outcome, as thousands of interactions occur to maximize health. For example, one study followed a group of healthy, untrained men through a six-week resistance training program and either consumed a 25g whey protein supplement fortified with 4000 IU vitamin D3 before bed, after bed, or a placebo. Both the pre- and post-bed protein groups improved compared to the placebo.

Understanding that all of these processes are continually improving and highly dependent on individual needs can aid you in reaching your specific goals. Working closely with your Apeiron Life team to optimize nutrition, recovery, and fitness requirements will ensure you're on the correct path to optimal health.

What about circadian misalignment?

Chrononutrition, or eating when best for the body, will likely be incorporated into the next national dietary guidelines, given the wealth of data linking meal timing with health. It has been shown in many studies that eating the bulk of calories earlier in the day when the body is primed to handle food is associated with better health. This is particularly true for carbohydrate intake. The body is less equipped to handle glucose later in the day.

Eating too close to bed can also disturb sleep. The process of breaking down food is thermogenic, and given that we require a drop in core body temperature in order to fall and stay asleep, eating too close to bedtime can fragment our sleep. Where protein intake before bed is required, such as after evening exercise, opting for a supplement rather than a larger, protein-dense meal might lead to more rapid digestion and better sleep.

Time-restricted feeding (eating during a specific window of usually 10 hours or less) has gained traction in recent years as a beneficial tool for weight loss and maintenance, as well as lowering cardiovascular disease risk. While more research needs to occur, some studies have shown that pre-sleep protein doesn’t impact our circadian rhythms. For example, lipolysis, or the breakdown of fats, can occur at night, and one study demonstrated this was not impaired by pre-sleep protein.

Our take:

Eating protein before bed has gained significant attention in the realm of nutrition and fitness. Contrary to the traditional notion of avoiding food before sleep, recent studies suggest that consuming protein-rich foods or supplements prior to bedtime may have notable advantages, especially for older adults. Sleep is the longest period of potential muscle loss, especially if we have under-fueled throughout the day. Within this 10-hour period there may be potential to encourage muscle repair and enhanced muscle protein synthesis by consuming a small amount of protein before bed. As of now, most of the research is limited but promising.

Supplements may be useful when we cannot otherwise acquire the nutrient in question through dietary sources. Prioritizing intake through whole food sources offers the crossover benefits of fiber, phytonutrients, vitamins, and minerals that typically accompany the poultry, fish, legumes, or other food sources. And never substitute a healthy diet for supplements alone.

Will this benefit you?

We usually reach peak muscle mass around age 30 and experience a steady decline into older age. But this decline may be minimized through physical activity and adequate protein intake. The benefits of maintaining a healthy skeletal muscle mass far exceed aesthetics alone. Healthy muscles promote ease of movement, injury prevention, and overall longevity.

Still curious to try it? If you do, here’s what to look out for:

The current research suggests ~40g of protein pre-sleep may be the optimal amount but be conscious of your individual response as to whether this works for you. Especially be aware of any sleep disturbance.

References & additional materials:

RDA US: https://www.dietaryguidelines.gov/sites/default/files/2020-12/Dietary_Guidelines_for_Americans_2020-2025.pdf

RDA NIH -https://www.ncbi.nlm.nih.gov/books/NBK56068/table/summarytables.t4/?report=objectonly

Protein intake meta-analysis - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7231581/

Testosterone and motivation in women -https://pubmed.ncbi.nlm.nih.gov/29266410/

Testosterone, cortisol, human competition - https://pubmed.ncbi.nlm.nih.gov/27103058/

Hormones responsible for muscle hypertrophy - https://pubmed.ncbi.nlm.nih.gov/29172848/

Skeletal muscle - https://pubmed.ncbi.nlm.nih.gov/25294644/

Where does dietary protein go? - https://pubmed.ncbi.nlm.nih.gov/26556791/

Plant-based protein - https://pubmed.ncbi.nlm.nih.gov/32664290/

Sleep and muscle repair - https://pubmed.ncbi.nlm.nih.gov/34074604/

Sleep, muscle, testosterone. -https://pubmed.ncbi.nlm.nih.gov/33400856/