Strength, Power, Stability

strength

The capacity to generate maximal force during a single voluntary contraction regardless of velocity

factors that impact strength

• Cross-sectional area

• Muscle architecture

• Neural activation

• Length tension relationship

• Gender and hormones

strength measurement

MMT, dynamometry

power

work performed per unit of time

• speed component

factors that impact power

muscle fiber time, neural activation, strength

stability

• Control of joint movement and position

  • Active (dynamic)

  • Passive

training principles

• SAID principle

• General adaptation syndrome

• Periodization

• Progressive overload

• Holton's Curve

specific adaptations to imposed demands

The body adapts specifically to the type, intensity, and duration of stress put on it

• Mode-specific: training gains occurs in the tissues and movement patterns that are stressed

• Intensity-specific: the intensity of the load determines the changes that occur

• Task-specific: training that mimics the desired activity best improves that activity

general adaptations syndrome

3 stage model developed to describe the body's physiological response to stress

• Alarm Reaction Stage: fight or flight response

• Resistance Stage: adapt and maintain function, elevated cortisol levels

• Exhaustion Stage: resources are depleted

periodization

Structured variation of training intensity, volume, and rest to optimize adaptation and reduce risk of reaching a plateau or overtraining

post-op rehab periodization

• Early: protect tissue healing, low load, focus on ROM and activation

• Mid: progressive strengthening, stability, neuromuscular control

• Late: functional retraining

  • Stairs, sit-to-stand, gait endurance

progressive overload

Gradually increasing the demands on a muscle to stimulate adaptation

• 1 rep max is the gold standard for strength testing and developing a training program

  • Time and resource consuming

  • May be inappropriate based on tissue healing/integrity

Holton’s curve

how to prescribe exercises

• What are the capabilities of the patient/client?

  • Including health of host and tissue integrity

• What is the goal of the activity?

• How close to the desired task can the activity be?

70-80% of 1RM

 increase 5% after 12 reps with good form

30-60% of 1RM

increase 10% after 25 reps with good form

less than 8

RPE when you should increase load/effort

maintenance under age 35

• 1/9th training volume

• Maintained muscle size and strength

maintenance ages 60-75

• 1/3rd training volume required for muscle size

• 1/9th for muscle strength

delayed onset muscle soreness (DOMS)

Muscle soreness after exercise due to microtrauma

• Onset 1-3 days

• Signs and symptoms

  • Tenderness to palpation

  • Feeling of weakness

  • Stiffness/reduced ROM

• Note: eccentric exercise more likely to cause

neuromuscular, physiological, cognitive

categories of effects of training

motor unit recruitment, neural drive

neuromuscular adaptations

motor unit recruitment

• Improved overall and selective motor unit recruitment

  • Number of motor units and synchronization

  • Fiber type (fast vs slow)

neural drive

• Improved firing frequency

• Neural drive improvements

  • Improved coordination between agonist and antagonists

  • Decreased inhibitory reflex activity

physiological adaptations

• Increased cross-sectional area of fibers

• Increased mitochondria, myoglobin, capillary density

• Improved energy storage

 

cognitive adaptations

• Improvement in frontal lobe function (executive functioning)

• Lower white matter atrophy

• Better working memory, processing speed, and response inhibition with unstable resistance training (free weight)

pediatric training

• Per NSCA: resistance training is relatively safe for youth

• Can improve muscular strength and power, cardiovascular risk profile, motor skill performance, athletic performance, resistance to injury, psychosocial well-being, and promote exercise habits

• Discourage powerlifting before skeletally mature (body weight sufficient to age 12)

• Free weights superior to machines

• Need appropriate supervision and a safe environment

 

geriatric training

• Muscle weakness, due to sarcopenia, is a normal effect of aging

  • 1-5% annually after age 30, 3-5% annually after age 60

• Older adults need to be loaded appropriately to impact strength

• May progress more slowly, need more recovery time