Darryn Willoughby, Ph.D., FACSM, FISSN, CSCS, CISSN, CNC

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_at_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-a, 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).

9
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 812 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

13
Weight Training Tips for Older Adults