Our body is composed of over 600 skeletal muscles, which may contribute from 40% to 50% of total body weight. Most skeletal muscles are attached to bony structures and are under our conscious control. These muscles perform essential tasks such as movement and breathing, postural control and body alignment, and heat production.
Moreover, muscle mass plays an important role in metabolism. To make a long story short, the more muscle you have, the more calories you burn at rest or during exercise. Keep in mind that energy expenditure (calories burned) is a crucial component of the energy equation. Energy balance is a state where the energy intake matches the energy expenditure, meaning that all calories consumed are promptly used by the body. When you consume more calories (energy input) than you expend (energy expenditure), the result is an energy surplus, which is stored as fat.
The problem is that as we age, we tend to lose muscle mass, which slows down our metabolism. This means that our ability to burn calories decreases with age. And if we don’t adjust our energy intake, the end result will be weight gain. The problem is that restrictive diets also pose harm to muscle tissue. This is because when our body doesn’t get enough carbohydrates from the diet, it has to breakdown protein for energy. And guess where this protein comes from? But do not despair. There are ways to guarantee healthy muscle mass and even prevent muscle loss.
First of all, muscle fibers are mostly comprised of protein, which is obtained from the diet. Thus, it is vital to consume enough of it. However, quality is as important as quantity. Dietary protein should supply all essential amino acids and enough of the nonessential ones. According to the 2010 Dietary Guidelines, most Americans get more than enough protein in their diets. However, people who restrict caloric intake (chronic dieters) and vegetarians may fall short on protein. Keep in mind that the adult RDA is 0.8 grams of protein per kilogram of body weight, meaning that a 150-pound adult requires around 54 grams of protein per day. The USDA’s My Plate recommends between 5 and 5 ½ ounce equivalents of protein for adult, moderate-active women. Bear in mind that a small chicken breast, a small hamburger, or a can of tuna corresponds to 3 ounce equivalents. For the vegetarians, 1 ounce of nuts or 1 cup of bean soup corresponds to 2 ounce equivalents of protein.
Exercise is also a great way to gain or maintain muscle mass. Several studies have shown that even older adults can benefit from muscle building exercises. The truth is that the muscle tissue is highly responsive to training stimuli, meaning that with appropriate exercise, muscles become larger and stronger. Resistance training, also known as weight-lifting or strength training, increases muscle mass, improves muscle strength, enhances body composition, and boosts metabolic rate. The ACSM recommends that most adults participate in at least two sessions of resistance training per week. A proper resistance training program should include exercises for all major muscle groups (chest, upper and lower back, abdominals, arms, and legs). A rest period of 48 hours between training sessions is advised in order to prevent overuse injuries.
As you can see, aging does not have to mean you are trading muscle for fat. To prevent muscle loss, keep a healthy diet that provides the recommended amount of protein and maintain an active lifestyle that includes muscle-building exercises at least twice a week. You’ll live longer and healthier.
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