Metabolism is the rate at which calories are converted from food to energy. Daily metabolic rates are based on the basal metabolic rate (BMR) and additional activity levels. BMR is the amount of calories burned with bodily functions. Additional calories are burned by maintaining an active lifestyle and following proper nutrition habits. Many factors affect BMR including aging. It is possible to offset the effects of aging on metabolism. Increases in metabolism are possible after age 50. (See References 1)
Physiological Factors
After age 30, physiological processes begin to decline. However, this decline does not become obvious until after age 50. There are declines in the number of cells in each organ that reduce metabolic rates. Declines in muscle fibers and muscle fiber size result in a decreased amount of muscle mass. Declines in cardiac output and oxygen volume result in decreased cardiovascular endurance. As a result of declines in muscle and cardiac output, there also may be an overall decline in physical activity. A less active body burns less calories resulting in decreases in metabolism of about 5 percent per decade. (See References 2)
Factors Increasing Metabolism
Factors that will increase metabolism can offset anticipated declines.Weight training after age 50 is effective for improving muscle mass or maintaining muscle mass and preventing decreases. Workouts should include all major upper body and lower body muscle groups. Upper body muscles include chest, back, shoulders, biceps and triceps. Exercise suggestions include dumbbell chest presses and shoulder presses. Lower body muscles include buttocks, quadriceps and hamstrings. Exercise suggestions include leg extensions and leg curls on selected resistance machines. Complete one to two exercises for each muscle group. Exercises should be completed in one to two sets of 12 to 15 repetitions. Breathing and correct form should be emphasized by working through a full range of motion.
Cardio Training
Weight bearing cardio exercises such as walking and elliptical training. Elliptical training machines offer higher intensity movements with legs simulating a jogging motion without impact to knees. Cardio training can be performed daily or every other day for 20 to 30 minutes. Increased intensity will increase the ability to provide blood and oxygen to the working muscles. Results include increases in circulation and breathing. Increased activity levels will improve metabolism. (See References 3)
Nutrition
Often, the frequency and amount of food eaten affects how quickly the food is converted to energy. Skipping breakfast gets the metabolism off to a slow start. Eating large, infrequent meals causes metabolic rates to slow down, keeping the food longer, as if in a starvation mode. Eating smaller, more frequent meals allows calories to be converted more quickly to energy and increases metabolism. Proper nutrition habits include following food pyramid guidelines. Focus on nutrient-rich, and fiber-rich fruits, vegetables and whole grains.
Considerations
Additional factors affecting metabolism are medications and nicotine. Nicotine increases metabolism; therefore, quitting smoking and reducing the effects of nicotine will lower metabolism. It is not recommended that smoking be continued as a weight control method. When an attempt is made at quitting, the best thing to do is to start an exercise program to prevent decreases in metabolism. Some medications also will affect metabolism in a negative way. Cortisone, for example, has been known to affect metabolism in a negative way. Consult with a physician concerning the effects of prescribed medication on metabolism.
References
- "Personal Training Manual"; American Council on Exercise; 1991
- "Understanding Nutrition"; Eleanor Whitney, Eva Hamilton & Sharon Rolfex; 1990
- "Keep Moving: Fitness Through Aerobics and Step"; Esther Pryor & Minda Goodman Kraines; 2000
- "Complete Food and Nutrition Guide"; American Dietetic Association; 2006
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