Importance of Resistance Exercise and Muscle Strengthening in Aging Muscles

1. Importance of Resistance Exercise and Muscle Strengthening in Aging Muscles Darryn Willoughby, Ph.D., FACSM, FISSN, CSCS, CISSN, CNC Exercise and Biochemical Nutrition Laboratory Exercise Nutrition and Resistance Training Research Unit Dept. of Health, Human Performance, & Recreation Baylor University, Waco, TX 76798, USA Darryn_Willoughby@baylor.edu; 254-710-3504

2. Aging and Muscle Loss • As a normal part of the aging process, individuals experience a loss of skeletal • muscle. This loss of muscle has been well documented in individuals over the age • of 50. • This loss of muscle tissue, with an associated loss of strength and mass, is referred • to as sarcopenia. • Sarcopenia can begin as early as the fourth decade of life. However, by the • seventh and eighth decades of life, a decrease in the maximal contractile strength • on the order of 20-40% for both men and women is observed. • The weakness associated with sarcopenia has been shown to be associated with • difficulty in rising from a chair and getting out of bed. • Decreases in muscle quality may also be a contributing factor in increased fracture • risk in older individuals. • Also associated with a decrease in muscle mass and muscle strength is a • decrease in the rate of force development in the muscles of elderly individuals.

3. Aging and Muscle Loss • Aging is associated with oxidative stress and subsequent local • inflammation in skeletal muscle. • Oxidative stress, by way of increased free radical generation, causes • oxidative modification and damage to protein, lipid, and DNA in skeletal • muscle. • This invariably leads to cellular dysfunction and muscle protein • degradation, as well as a decline in muscle mass and function.

4. Sarcopenia • Involuntary loss of skeletal muscle mass, strength, and function. • Part of the normal aging process. • Enhanced by morbidity, chronic malnutrition, a sedentary lifestyle, and smoking. • Limits Functional Capacity • Increases the risk for incapacitation, falls, fractures, and a dependent lifestyle. CT Scans Young, healthy muscle Elderly muscle

5. Consequences of Sarcopenia • Decreased resting energy expenditure • Decreased insulin sensitivity • Decreased muscle mass and strength • Increased risk of physical disability • Increased risk of falls • Increased risk of mortality

6. Sarcopenia is a Multi-Factorial Disorder • Decreased levels of sex hormones (testosterone and DHEA) • Decreased levels of growth hormone and insulin-like growth factor 1 (IGF-1) • Increased cytokine production (i.e., IL-1, IL-6, TNF-α, etc.) • Neuromuscular changes • Smoking • Physical inactivity • Malnutrition (especially protein deficiency) • As a result of this loss of muscle mass and strength, older individuals experience a decreased quality of life. • The lack of physical exercise is one of the most important predictors of disability in elders.

7. Low Protein + Low Exercise = Sarcopenia • Sarcopenia starts to set in around age 45, when muscle mass • begins to decline at a rate of about 1 percent per year. • This gradual loss has been tied to protein deficiency, lack of • exercise, and increased frailty among the elderly. • The human body reacts to protein deficiency by taking amino • acids (the building blocks of proteins) away from muscle • tissue and other areas of the body. • The process, in which the body basically metabolizes itself, is • called catabolism and leads to muscle loss and weakness. • Currently, the recommended daily intake is 0.8 grams per • kilogram of body weight (established by the ADA), or 56 • grams for a 154-pound person. • However, very active older individuals might instead benefit • from about 1.2 grams per kilogram body weight.

8. Aging Effects on Skeletal Muscle • Strength training remains highly effective • in maintaining muscular strength • throughout life. • However, after about age 60, strength • levels fall more rapidly, independent of • training. • This is probably influenced by changes • in hormones such as testosterone and • growth hormone, which appear to • decline more dramatically after age 60. • Reduction in the circulating • concentration of these hormones will • result in a shift in the balance between • muscle protein synthesis (anabolism) • and protein breakdown (catabolism). • The decreased strength is due to atrophy • of muscle fibers.

9. Better control of symptoms of • diabetes, arthritis, osteoporosis, • back pain, and depression. • Prevents falls due to restoration • of balance. • Improved posture and stability. • Increased flexibility and range of • motion. • Strengthens the bones and • reduces risk of fractures. • Improves muscle strength and • endurance. • Healthy, independent, and • functional life. Benefits of Weight Training for Older Adults

10. Benefits of Weight Training for Older Adults • It is never too late to start on a muscle conditioning and weight training program. • Weight training is especially important to slow the process of sarcopenia (age-related skeletal muscle loss). • Regular weight training has shown to: • reduce blood pressure • improve blood cholesterol levels • improve insulin sensitivity • speed-up gastrointestinal transit • increase bone mineral density • alleviate low-back pain • ease arthritic discomfort • improve cardiovascular function • relieve depression • reduce body fat • improve functional abilities

11. Exercise and Aging • Cardiovascular or Aerobic Activities. • Achieve the aerobic activity recommendation through one of the following options: • A minimum of 30 minutes of moderate-intensity physical • activity per day (such as brisk walking) most days of the week • A minimum of 20 minutes of vigorous-intensity physical • activity (such as jogging or running) 3 days a week • Resistance Training Activities. • Two days a week, incorporate strength training into your routine. • Strength training activities, such as weight lifting, maintain • and increase muscle strength and endurance. • A goal to reach towards is completing 6-8 strength training • exercises, with 8–12 repetitions per exercise.

12. General Weight Training Guidelines for Older Adults • Prior to each workout, it's essential to warm up sets before lifting weights. • Start with approximately 5 minutes of stretches for all the muscle groups to be trained. Then, • using 50% of your normal workout weight, perform 1-2 warm up sets for 15 repetitions. • Initially you will have to experiment with different weights to determine how much you can • safely use while effectively stimulating the muscles. • Over time you'll find that the weights you normally use become lighter as your muscles • become stronger. When this occurs increase the weight slightly to allow increased stimulation • to the muscle fibers. This will allow for continued growth and development. • If your new to weight lifting or haven't lifted for over 3 months, begin with 2 sets per exercise. • Increase one set to each exercise each month until you get to 4 sets per exercise. • Patience is key and is essential to prevent injury and allow the body to adapt and grow • stronger. • The weight that you've chosen should allow you to safely perform 10-12 repetitions for each • set. The final few repetitions are generally more difficult to perform than the first few but • should not cause excessive strain in order to complete. • Generally 60-90 seconds of rest between sets is sufficient, however, be sure you've had • adequate time to catch your breath.

13. Start a weight training program and work at your pace. Do not hurry. • If you want a fit physique there is no substitute for resistance training. • Learn the best weight training practices. Its easier to learn correct methods than to unlearn the wrong ones. • Start with the most appropriate weight training exercises and adhere to • correct form. • Stay injury free – Make sure and perform exercises correctly and employ a proper warm up as injuries in older people take a longer time to heal. • You do not have to lose muscle mass with age. Rather you can maintain what you have and build some more quality muscle mass with weight training. • A good stretching and warm up and warm up program is absolutely crucial to develop mobility, strength and cardiovascular endurance. • Weight Training can be a fountain of youth. Use this gift and work consistently. • Proper nutrition becomes even more important when you train with weights. • Desire and dedication will show on your body. If you want better health • outcomes relative to exercise then there is no substitute to hard work. Weight Training Tips for Older Adults