The Centers for Disease Control and Prevention recommends you hit all the major muscle groups with resistance training at least twice a week for good health. Strength training improves your confidence and your appearance. It helps you better perform simple daily activities from getting dressed to cleaning the kitchen. Strength training also prevents the inevitable loss of muscle mass that happens when you fail to move. Use your muscles or lose your muscles.
If you are in a seated job, bedridden or simply avoid physical activity, you lose muscle tone. Your muscles need to face resistance – from your body, weights, water or elastic – to rebuild and stay strong. Astronauts, for example, who are exposed to low gravity environments lose muscle mass at an accelerated rate because their bodies don’t experience the resistance of gravity. If your body senses that you do not need the muscle for daily function, it will stop supporting them and may even feed off the muscle for energy. It takes more metabolic effort for your body to support muscle tissue, so if your muscles aren't used your body isn’t going to bother putting in that effort and wasting resources needed for survival.
As you grow older, your muscles naturally atrophy. Starting around age 25, this condition, called sarcopenia, sets in. After age 45, you lose approximately 1 percent of your total muscle mass per year if you do not do targeted exercises to keep it, notes the U.S. Department of Agriculture. By the time you reach age 65, the weakness and lack of tone related to sarcopenia becomes significant.
Without significant muscle mass, your metabolism suffers. Muscle burns more calories than fat tissue. A body with a higher proportion of muscle burns a greater number of calories at rest in a more efficient manner. As a result, you have an easier time managing your weight. Being overly fat – even if you are of normal weight -- increases your risk of certain diseases, including heart disease, stroke, some cancers and Type 2 diabetes. Loss of muscle mass can also lead to loss of function. It may be harder to do chores, play with your kids, carry groceries or walk up the stairs. As you age, loss of muscle impedes balance and can cause dangerous falls and limit your ability to care for yourself.
How fast you lose muscle mass and function depends on how you care for your body. Engaging in regular strength training slows the rate at which you lose muscle and can actually increase muscle mass. Your two-day per week minimum regimen should include at least one exercise to address the back, legs, chest, arms, abdominals and shoulders with eight to 10 repetitions. The weight you use should bring you to fatigue by the last one or two repetitions. Give yourself at least 48 hours between strength-training sessions so your muscles can recover and grow stronger. As you progress, add an additional day and additional sets of exercises. If the activity becomes too easy, amp up the weights so you continue to reach fatigue by the last couple of repetitions. Combine your strength-training routine with a regular cardiovascular fitness plan that has you moving at a moderate intensity at least 150 minutes per week. Try brisk walking, dancing or light cycling.
If you experience an extreme and sudden onset of weakness, consult your physician. Certain conditions such as Guillain-Barre syndrome muscular dystrophy, osteoarthritis, rheumatoid arthritis and several autoimmune disorders can cause an acceleration of muscle loss. These and other diseases that cause atrophy attack a nerve that connects to the muscle.
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