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 [email protected]; 254-710-3504 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
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 [email protected]; 254-710-3504 Importance of
Resistance Exercise and Muscle Strengthening in Aging Muscles
Slide 2
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. Aging and Muscle
Loss
Slide 3
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.
Slide 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
Slide 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
Slide 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-, 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.
Slide 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.
Slide 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.
Slide 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
Slide 10
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 Benefits of Weight Training for Older Adults
Slide 11
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 812 repetitions
per exercise. Exercise and Aging
Slide 12
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. General Weight Training Guidelines for Older Adults
Slide 13
1. Start a weight training program and work at your pace. Do
not hurry. 2. If you want a fit physique there is no substitute for
resistance training. 3. Learn the best weight training practices.
Its easier to learn correct methods than to unlearn the wrong ones.
4. Start with the most appropriate weight training exercises and
adhere to correct form. 1. 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. 2. 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. 3. A good
stretching and warm up and warm up program is absolutely crucial to
develop mobility, strength and cardiovascular endurance. 4. Weight
Training can be a fountain of youth. Use this gift and work
consistently. 5. Proper nutrition becomes even more important when
you train with weights. 6. 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