In a previous article we spoke about the effectiveness of protein shakes when consumed around training. We also discussed what happens around exercise with respect to muscle protein balance, and how in order to maximise your lean muscle building, strength and recovery capacity; muscle protein synthesis should be high, while protein breakdown should be kept to a minimum.
Immediately after a resistance training session protein breakdown exceeds synthesis. As this stage of recovery progresses, and if a post-workout shake is provided then eventually synthesis will be greater than breakdown for a short period of time. Protein breakdown will always exist, and in particular during times of fasting or physiological stress; protein breakdown will be at its highest.
Night-time Muscle Recovery | The problem with sleep
When you’re tucking yourself in to bed at night you’re about to embark on, hopefully, what will become a 7-8 hour period full of restful sleep and recovery. However one problem with this period is that you aren’t feeding your body with the nutrients that is sometimes needs. This will become a 7-8 hour nutritional fast where your body could be missing out. In terms of digestion and utilisation of nutrients, we call this period the post-absorbtive phase.
During the first 2 hours or so after a meal the body is in what’s referred to as the post-prandial phase. During this time the body is working like a machine to synthesise new proteins and replenish glycogen stores in the muscles and liver. Once the nutrients have been delivered during this phase for storage, the post-absorbtive period is what follows. This is when the body is looking to use those stored nutrients as energy. In order to maintain blood glucose and tissue metabolism, the body starts to send out stored nutrients and amino acids from the muscles in to the bloodstream.
…And when amino acids are leaving muscles, tissue breakdown must occur to keep up with the demand. Simply, during times of hunger, fasting, or whilst you’re sleeping during your overnight fast; muscle tissue breakdown is occurring. Your night time sleep will likely be the longest post-absorptive period, and therefore the most catabolic.
Research has confirmed this, and shows that after an overnight fast muscle protein breakdown exceeds synthesis. It’s also interesting to note that in organs such as the stomach, liver and intestines the opposite seems to be true, in that synthesis during these times often outweighs breakdown. It is believed therefore that during the night that muscle tissue is
broken down to ‘feed’ the tissues of the gut, liver, intestines and other organs around the splanchnic region (5).
Now you could say to yourself that you are going to wake up at set time intervals throughout the night for a quick shot of protein. I have even heard of people waking up in the middle of the night to pop a few BCAA’s to help try to bridge the fast with some amino acids. However we all know that sleep is essential and breaking your sleep cycle could have negative effects on your overall physique and recovery. So what’s the more practical and effective solution, for when you’re awake?
The protein solution
Consume a slow-digesting source of protein such as casein as a pre-bedtime or late evening snack. Casein is the main form of protein found in cow’s milk, making up approximately 80%, with the other 20% coming from whey, and is referred to as a slow digesting protein compared with whey, egg and soy because it clots in the stomach.
In a number of studies, casein did not increase protein synthesis like whey protein post-workout (1, 6, 7). However, casein works through preventing protein breakdown and promoting an anticatabolic effect that is not found with whey protein. Casein has also been shown to be better to combat feelings of hunger, so is more beneficial to be taken prior to long periods without eating.
Another difference between whey and casein is that consuming a whey protein shake causes a quick and high rise in blood amino acid levels. This is great news most of the time, and exactly what you want to be happening around your workout. However these high blood amino acid levels also begin to drop rapidly once they hit their peak. After around 1 hour blood amino acid levels are elevated by about 300%, after 2 hours drop to about 92% and after 4 hours you’re back to baseline. On the other hand, casein produces a moderate but prolonged spike in blood amino acid levels for around 4-5 hours before there’s a drop off.
After 2 hours blood amino acid levels are elevated by around 35%, whereas after 4 hours they are still elevated to a similar amount (1, 3). In addition to this In some studies milk protein (80% casein 20% whey) has been shown to lead to elevated blood amino acid levels for up to 8 hours (2), potentially due to the different ways in which casein and whey work, and likely having a synergistic effect when taken together. Whey protein has also been shown to enhance sleep quality and next day alertness (4).
Although due to the unique anti-catabolic nature of casein protein making it more beneficial at this time of day, a small amount of whey protein added to your casein, a milk protein blend or timed-release protein with a mixture of different proteins would be the best option, and may even be superior to casein protein alone. A shake consisting of 30g-50g of protein should do the trick before bed to help reduce muscle breakdown, overnight catabolism and to maximise your lean muscle building potential and overnight recovery.
Take Home Message
✓ For most your overnight sleep is the longest fasted period, and what we refer to as the post-absorbtive
✓ Overnight, muscle protein synthesis drops while muscle protein breakdown elevates, leading to a more catabolic state.
✓ Casein protein can clot in the stomach allowing a steady ‘drip feed’ of amino acids in to the blood stream throughout the night.
✓ Taking this one stage further, the addition of a small amount of whey protein to the casein, such as in a milk protein blend or timed-release protein, could drip feed the muscles for a greater period of time than casein alone, decreasing protein breakdown, increasing synthesis of new proteins, and potentially even help to improve your sleep quality.
✓ 30 to 50g of protein before bed or as a late evening snack, depending on preference, is considered the optimal ammount.
Boirie Y, Dangin M, and Gachon P. (1997). Slow and fast dietary proteins differently modulate postprandial protein accretion. Proc Natl Acad Sci U SA 94: 14930-14935.
Bos, C., Mahe, S., Gaudichon, C., Benamouzig, R., Gausseres, N., Luengo, C., Ferriere, F., Rautureau, J., and Tome, D. (1999). Assessment of net postprandial protein utilization of 15N-labelled milk nitrogen in human subjects. British Journal of Nutrition 81: 221-226. Dangin, M., Boirie, Y., Garcia-Rodenas, C., Gachon, P., Fauquant, J., Callier, P., Ballevre, O., and Beaufrere, B. (2001).
The digestion rate of protein is an independent regulating factor of postprandial protein Am J Physiol Endocrinol Metab 280:E340-E348. Markus CR, Jonkman LM, Lammers JH, Deutz NE, Messer MH, and Rigtering N. (2005).
Evening intake of alpha-lactalbumin increases plasma tryptophan availability and improves morning alertness and brain measures of attention. Am J Clin Nutr 81: 1026-1033. Meek, S., Perrson, M., Ford, G., and Nair, K. M. (1997).
Differential regulation of amino acid exchange and protein dynamics across splanchnic and skeletal muscle beds by insulin in healthy human subjects. Diabetes 47(12): 1824-1835. Tang, J., Moore, D., Kujbida, G., Tarnopolsky, M., and Phillips, S. (2009).
Ingestion of whey hydrolysate, casein, or soy protein isolate: Effects on mixed muscle protein synthesis at rest and following resistance exercise in young men. J Appl Physiol 107: 987-992. Tipton, K., Elliott, T., Cree, M., Wolf, S., Sanford, A., and Wolfe, R. (2004).
Ingestion of casein and whey proteins result in muscle anabolism after resistance exercise. Med Sci Sports Exerc 36: 2073-2081.[/su_spoiler]