Nutrition and muscle protein synthesis: a descriptive review
Amino acids are the building blocks/ monomers of proteins, wheras proteins are polymers of amino acids, which are linked together through. Exercise prescription and/or nutritional advice, whether possessing therapeutic occurs depends greatly on a synergistic relationship between diet and exercise. Muscle export of amino acids can result in large protein losses or sarcopenia. Luckily, there is a more straightforward answer: “Amino acids are the building blocks of protein,” says Elizabeth Shaw, R.D., an adjunct nutrition.
Research continues to focus on the mechanisms contributing to sarcopenia. Although protein synthesis and ultimately skeletal muscle mass are regulated by a host of factors, the fundamental prerequisite for muscle protein synthesis is dietary derived amino acids.
The purpose of this review is to highlight recent research examining the role of protein in the prevention or management of sarcopenia and provide recommendations on the amount of protein needed with each meal to preserve skeletal muscle mass in ageing.
The majority of studies suggest that a moderate-to-large serving of protein or amino acids increases muscle protein synthesis similarly in both young and elderly [ 6711 — 17 ]. Historically, the majority of protein metabolism studies have focused on the anabolic response to ingestion of protein or amino acids alone.
However, when protein and carbohydrate are coingested, elderly respond with a diminished anabolic response compared with their younger counterparts. A subsequent study confirmed these results [ 19 ]. Fortunately, a modest bout of physical activity may be able to sensitize ageing muscle to subsequent nutritional stimuli.
We have recently shown that 45min of treadmill walking in older individuals, the evening prior to an hyperinsulinemic—euglycemic clamp, restores the ability of insulin to stimulate muscle protein synthesis [ 4 ]. More recently, we demonstrated that ingestion of leucine-enriched essential amino acids stimulates muscle protein synthesis to a similar extent in young and elderly although the response was delayed in the elderly during the first 6 hours following exercise [ 21 ].
These data provide further supporting evidence that regular physical activity plays an important role in restoring or maintaining the normal protein anabolic response in the skeletal muscle of older individuals.
However, several recent studies have adopted a more practical approach and sought to examine the ability of protein-rich foods e. Although many of these studies have focused on a younger population [ 2324 ], they are important as they more closely reflect responses to actual dietary practices and hence provide information on how meal choices may influence accrual of muscle mass and ultimately functional capacity.
In one study directly comparing young and elderly, Symons et al.
Should protein intake be increased in the elderly? The adequacy of the recommended dietary allowance RDA for protein has been the subject of renewed debate over the past 12 months [ 25 — 30 ]. The current recommendation for protein intake for all men and women aged 19 years and older is 0.
The recommendations were established by the Institute of Medicine and based on short-duration nitrogen balance studies in young adults [ 3132 ]. This gives them some interesting abilities that no other amino acids have.
One big perk of BCAAs is that they help prevent muscle breakdown. Leucine is the key BCAA in this process. Here's more on why leucine is so important for maintaining and building muscle. BCAAs also provide fuel for exercise. During an intense workout, the unique structure of BCAAs allows them to act as fuel for your muscles.
Amino Acids in a Balanced Diet | Healthy Eating | SF Gate
And finally, they may help you slim down: Sources of BCAAs 1. Drinks with BCAAs have become very popular and come in lots of great citrus and fruit flavors that don't taste like you're just drinking protein. These products are fine to use right after exercise or during long training session over 90 minutes. Whey protein or chocolate milk: A simple shake with whey protein will deliver all the BCAAs that you need along with all the other essential amino acids to round out your muscle building and recovery efforts.
Your Guide to the Benefits of BCAAs and Essential Amino Acids
Or you can simply have a glass of chocolate milk to serve as your nutritional recovery aid. Milk is naturally loaded with BCAAs and the little added sugar from the chocolate will further aid in recovery after a longer exercise session. Fish, eggs, lean beef, chicken, and turkey all contain ample amounts of these key amino acids.