Week 9 - Resistance Training Flashcards
What is the percentage of decrease of peak muscle force from age 40-65?
25%, so about 1% per year
What is the aging process related to muscle fibers.
- Motor neurons die
- Muscle fibers die
- Reinnervation of a few fibers by neighbouring Type 1 motor neurons
- Increase size of rescuing motor units
- Change in Type 1 vs Type 2 ratio
What are the structural changes in the neuromuscular junction?
- Flattening of cell membrane –> increases the distance between the receptors and decreases the quality of transmission
- Myelin sheath infiltration –> can migrate to synaptic cleft and partly block acetylcholine which decrease signal transmission
What are the consequences of structural changes in the neuromuscular junction?
decreases speed and strength of muscle contraction
What are the health-related benefits of resistance training?
- body composition: increase lean tissue mass + metabolic rate + daily expenditure –> decrease body fat of up to 9%
- blood pressure: small decrease in resting systolic and diastolic BP –> decrease risk of stroke and coronary artery disease
- bone mass: improves bone health –> reduces risk of osteoporosis
- glucose tolerance: improvements in glucose tolerance and insulin resistance
- lower back pain: increased strength of vertebral muscles = maintain muscular balance = lower back pain
- blood lipids: lowering total cholesterol and triglyceride levels
A reduction of only ___ mmHg in SBP and DBP lower stroke risk by 14 and 17% respectively, and the risk of coronary artery disease by 9% and 6%, respectively.
2 mmHg
Is resistance training as effective as aerobic training to decrease blood pressure and insulin resistance in OA?
No!
Aerobic = 3-5 mmHg
RT = 2-3 mmHg
What was the goal of the pioneer study (1990)?
to determine the feasibility and physiological effects of high RT in frail OA (10 subjects)
What was the target population and range of age?
Mean 90+
Range 86-96
How many had a history of falls and how many used ambulatory assistive devices?
- Falls: 8
- Assistive devices: 7
What were the exercise parameters? (duration, frequency, intensity)
- Duration: 8 weeks
- Frequency: 3/week
- Intensity: 50-80% of 1 RM
Which muscles were they targeting, and how? What were the safety measures involved?
Progressive RT: knee extensors + flexors
- 3 sets of 8 reps (total of 24 reps)
- concentric + eccentric contractions
- week 1: load = 50% 1RM (1RM remeasured every 2 weeks)
- week 2-8: load = 80%
Safety: monitoring of HR and BP (ensure little variation during training): less than 10 mmHg systolic BP and less than 5 mmHg for HR
What were the results of the experiment with regards to completion, attendance and physical parameters?
- 9/10 completed program
- Attendance 98.9%
Improvement in physical parameters:
- knee extensors strength increased by 174%
- mid thigh muscle area increased by 9%
What were the results of the experiment with regards to functional level?
Improvement in functional level:
- no change in habitual gait speed but 48% improvement in tandem gait speed
- 2 subjects no longer used canes at the end
- 1/3 subjects who could not initially rise from a chair without use of the arms became able to do so
What is the overload principle in OA?
Capacity of the muscle cells to exert force increases and decreases relative to the demands placed on the muscular system
What happens to OA who live sedentary lifestyles?
sedentary lifestyle –> demands on muscles decreases –> muscle cells decreases in size (atrophy) –> muscles decreases in strength and mechanical force
What are the 3 types of resistance training?
fixed-weight machines, free weights, resistance bands
What are some characteristics and considerations when creating a resistance training (RT) program?
safe, effective, convenient, enjoyable (adherence)
What are the advantages of fixed-weight machines?
- can target the larger muscle groups more efficiently because the body is pretty stable
- easier for proper movement technique (speed and quality)
- low risk of injury (if load is right)
What are the disadvantages of fixed-weight machines?
- minimal resistance can be too great for frail OA
- increments in resistance can be too large for frail OA
What is the main difference between seated and standing cable pulley machines?
Standing allows for the use of postural muscles to be much more involved = closer to ADLs
What are the benefits of free weights?
- more convenient vs machines (i.e. practicality)
- allow for endless variation of exercises
- takes some skill to learn proper technique
- functional movement patterns that mimic both everyday activities and sport-specific activities
What are the benefits of resistance band?
- more convenient vs mschines (i.e. practicality)
- allow for endless variation of exercises
- takes some skill to learn proper technique
- functional movement patterns that mimic both everyday activities and sport-specific activities
- easier for movement initiation
- lower risk of injury
How to select exercises?
Stress all major muscle groups so that muscular balance can be maintained.
Should incorporate both single-joint and multiple-joint exercises for maximal effect.
What are single-joint exercises?
one specific muscle group (ex: bicep curls)
What are multiple-joint exercises?
targets more than 1 muscle group (ex: lunges)
Are single- or multiple-joint exercises closer to activities of daily living?
Multiple-joint exercises
Give some examples of multiple-joint exercises.
Squat, leg press, lunge, stair step, etc.
What is resistance?
- Also known as “load”
- Amount of force exerted against working muscles
How do we express resistance?
- Absolute terms (weight in lbs or kg)
- Relative terms (i.e. % or max force) = 1RM
Describe the types of load (heavy, moderate and light) in terms of 1RM?
- 90 or more % of 1 RM = heavy loads
- 70-90% of 1 RM = moderate loads
- less than 70% of 1 RM = light loads
What can be an alternative to 1RM for a frail OA?
8RM
What is the rep range for 8RM?
8-9
What is the proper load for OA, beginning lifter?
- 45-50% of 1RM needed to increase dynamic muscular strength
What is the proper load for OA, frail OA?
Frail OA can tolerate loads up to 80% 1 RM.
What is the proper load for OA, healthy OA who are advanced lifters?
- 80% of 1RM recommended to stimulate muscle cell hypertrophy and strength development
Is high RT better than variable RT to improve strength and functional performance in OA?
Yes
What was the purpose of the high RT and variable RT study?
Compare the effects of high-resistance training at 80% max strength (1 RM) vs variable-resistance training (80%, 65%, 50% 1RM) for 6 months.
What were the results of the high RT and variable RT study?
- both groups increased strength, no difference in changes
- no change in O2 uptake during daily activity tasks (DAT)
- significant time effect for heart rate and perceived exertion
What should be a priority in training program for OA?
optimal stimulation of the large muscle groups in the legs (e.g., leg press) and the upper body (e.g., bench press, seated row)
Why should you stimulate large upper and lower body muscle in training program for OA?
to increase health benefits (body comp, bone mass, BP, glucose tolerance, blood lipids) and performance benefits (walking endurance)
Why should you always exercise larger muscle groups first?
To allow increase intensity and decrease muscle fatigue in large muscle groups
What are the recommendations for sets and safety tips in OA?
- should not exceed 2-3 sets for the OA
- the highest BP and HR will occur in the last few repetitions of a set
avoid sets to failure in OA (especially in those with cardiovascular problems)
What are the load and repetition recommendations for OA in training goal? (strength, power, muscular endurance)
- strength: 60-80%, 8-10 reps
- power: 40-60%, 6-10 reps
- muscular endurance: 65% or less, 12-15 reps
To improve functional capacties of OA, should we focus more on training muscle strength or muscle power?
Power
What are the 2 benefits of resistance training in OA?
- preserve independent living in OA
- Improve health and longevity in OA
What is the functional activities related to ankle dorsiflexion and plantar flexion?
walking, mobility, getting up from a chair
What is the functional activities related to knee flexion and extension?
- required for all mobility activities
- can prevent falls
What is the functional activities related to hip abduction and adduction?
lateral stability and increase stability with walking
What is the functional activities related to abdominal muscles?
- core stability
- posture, balance and mobility
What is the functional activities related to chest?
- pushing and carrying objects
- controls upper body during gait
What is the functional activities related to back?
- pulling activities
- posture of the spine
What is the functional activities related to biceps and triceps?
- many ADLs (carrying groceries, putting on clothes)
What is the functional activities related to shoulders?
- carrying
- reducing the impact of falls
How to perform RT in a safe way for OA?
- warm-up for at least 10min before training
- start with low resistance and gradually add repetitions, intensity (load), and sets
- conduct exercises through a full pain-free ROM
- discontinue any exercise that cause pain or decrease resistance
- never hold your breath –> exhale during exertion phase and inhale during release phase
- avoid hyperextending joints
- allow 48 hours between RT sessions using same muscle groups
