How To Preserve Muscle Mass

Preserving muscle mass and preventing the loss of lean body mass can maintain muscle strength and cardiovascular health. Age-related muscle loss is called sarcopenia, and is a natural part of aging — your age and sex play a strong role in how quickly you lose fitness. However, sarcopenia isn’t exclusively restricted to the elderly, it can also be caused by muscle disuse, immobilization, malnutrition and inflammatory diseases, even in young adults. Overall, less muscle mass means more weakness and less mobility. 

Taking a few days break from your exercise routine is actually good for you, allowing your muscles to recover and helping you reach your long-term fitness goals. However, taking too long of a break can cause muscle loss and decreased cardio endurance. How long is too long? 

According to the American Council on Exercise, each body responds in its own way to exercise stimuli. So the amount of time it takes to respond to a reduced amount of exercise will vary from person to person. But in general, you can expect endurance to start fading after around two weeks, and your overall muscular strength to fade about a month after cessation of your exercise routine. 

What should I eat to preserve muscle mass?

Proteins in foods become available for use by the body after they have been broken down into their component amino acids. Nine of these amino acids are considered essentials, and the overall quality of your dietary proteins correlates with the content of these indispensable amino acids. 

Before we dive, a few definitions: 

• Protein:  The nutrient’s name comes from the Greek word proteos, which literally means “primary” or “taking first place,” an indication of the importance of protein in nutrition. Protein can be found throughout the body, primarily in the skeletal muscle, organs, skin and blood. 
• Amino Acids: Amino acids are the molecules that make up proteins. Together, amino acids and proteins are the building blocks of muscle. 
• 9 Essential Amino Acids - histidine, isoleucine, leucine, lysin, methionine, phenylalanine, threonine, tryptophan, and valine. 
• Branched-Chain Amino Acids (BCAAs) refer to the essential amino acids valine, leucine and isoleucine. 
• Non-Essential Amino Acids - glutamine, glutamate, and alanine assume particular importance because of their versatility in the overall metabolism of amino acids. 

The quality of protein depends upon its digestibility but primarily on its indispensable amino acid composition — both the specific amounts and the proportions of these amino acids. Protein-containing foods can be divided into two categories: 

• high-quality or complete proteins
• low-quality or incomplete proteins

A complete protein contains all the indispensable amino acids in the approximate amounts needed by humans. Sources of complete proteins are mostly found in animal sources, such as milk, yogurt, cheese, eggs, meat, fish, and poultry. Incomplete proteins, or low-quality proteins, are derived from plant foods like legumes, nuts, seeds, vegetables, and cereals/ grains. Most plant foods tend to have too little of one or more indispensable amino acids; with the exceptions of soy protein, quinoa, and chia seeds, which are complete proteins. The body cannot make a protein if an amino acid is missing. [1]

The skeletal muscles readily absorb and use amino acids after consuming a meal, especially when the meal contains a mix of carbohydrates, fiber, fat and high protein. Exercise also further encourages amino acid uptake by muscles, which is why it is recommended to consume a drink or meal with an appropriate carbohydrate-to-protein ratio within 30 minutes after your workout. 

Plant versus animal proteins

Plant-based proteins are typically missing one or more essential amino acids, most often methionine and/ or lysine, and have lower digestibility when compared to animal-based protein sources. Animal-based protein sources may also be higher in leucine, which is helpful in promoting muscle protein synthesis. [1]

Protein timing

Muscle protein synthesis over a 24-hour period appears to be greatest when you consume a consistent amount of protein at each meal throughout the day, versus a disproportionate amount of protein at one meal versus the other. In other words, consistency is key to maximize muscle protein synthesis — incorporate it at every meal. [1]

How much protein do I need?

The Recommended Dietary Allowance (RDA) reflects the average daily amount of a nutrient considered adequate to meet the needs of most healthy people. They are established for gender and life stages. Two RDA values have been set, gram/day and gram/kg body weight/ day. 

Age	Male	Male	Female	Female	Pregnant	Pregnant	Lactation	Lactation
19-30 years	56 g/ day	0.80 g/ kg/ day	46 g/ day	0.80 g/ kg/ day	71 g/ day	1.10 g/ kg/ day	71 g/ day	1.30 g/ kg/ day
31-50 years	56 g/ day	0.80 g/ kg/ day	46 g/ day	0.80 g/ kg/ day	71 g/ day	1.10 g/ kg/ day	71 g/ day	1.30 g/ kg/ day
51+ years	56 g/ day	0.80 g/ kg/ day	46 g/ day	0.80 g/ kg/ day	71 g/ day	1.10 g/ kg/ day	71 g/ day	1.30 g/ kg/ day

What does research say about protein consumption?

• While the RDA includes a safety variance of over 20%, it does not necessarily provide for maximum protein utilization, and it has been suggested that the current RDA for protein is not adequate, especially for older adults. [1]

• After a workout, it’s important to consume a carbohydrate-to-protein ratio of 3:1 or 4:1 to enhance glycogen storage and muscle protein synthesis. [2, 3] For example, a snack that has about 22 grams of carbs and 8 grams of protein. 
• An intake of 20 grams of protein (whey) per meal maximally stimulated muscle protein synthesis in rested muscle and exercised (resistance training) muscle in young men. [4]
• For older adults, intakes of 25-35 grams of high-quality protein per meal have been recommended. [1]

Sample meals and snacks that are high in protein. 

• Grilled chicken with roasted vegetables and rice. 
• Egg omelet with avocado spread on a whole grain toast. 
• Tuna and crackers
• oatmeal  with whey protein, banana and almonds
• Cottage cheese and fruit
• Unsweetened Greek yogurt, berries and granola
• Protein shake and a banana

The bottom line is that several factors affect your muscle mass. Consume a balanced diet with good sources of protein. And make sure you are consuming protein throughout the day.

If you need to cut back on your exercise but don’t have to stop completely, even a minimal amount of strength or cardio activity can prevent you from losing all your progress. It is best to find the right routine that can help you enjoy regular exercise and stick with it long-term. 

Sources: 

1. Advanced Nutrition and Human Metabolism; 7th edition; S. Gropper, J. Smith, T. Carr. Page 175-240.
2. Ivy JL, Goforth HW Jr, Damon BM, McCauley TR, Parsons EC, Price TB. Early postexercise muscle glycogen recovery is enhanced with a carbohydrate-protein supplement. J Appl Physiol (1985). 2002;93(4):1337-1344.
3. Zawadzki KM, Yaspelkis BB 3rd, Ivy JL. Carbohydrate-protein complex increases the rate of muscle glycogen storage after exercise. J Appl Physiol (1985). 1992;72(5):1854-1859.
4. Witard OC, Jackman SR, Breen L, Smith K, Selby A, Tipton KD, Myofibrillar muscle protein synthesis rates subsequent to a meal in response to increasing doses of whey protein at rest and after resistance exercise. Am J Clin Nutr. 2014; 99:86-95.