Chapter 6 Flashcards
Muscle performance
capacity of a muscle to do work (force x distance)
Key elements of muscle performance
strength, power, endurance
Resistance training
any form of active exercise in which dynamic or static muscle contraction is resisted by an external force applied manually or mechanically
Examination and Evaluation
- consider underlying pathology, stage of tissue healing, age, overall level of fitness, ability to cooperate and learn
- foundation to determine whether a program of resistance exercise is warranted and can improve current level of function/prevent dysfunction
Muscle strength
broad term that refers to the ability of contractile tissue to produce tension and a resultant force based on the demands placed on the muscle
Muscle power
strength and speed of a movement and is defined as muscle work (force x distance) produced by a muscle per unit of time (force x distance/time); AKA rate
Muscle endurance
ability of a muscle to contract repeatedly against a load, generate and sustain tension, and resist fatigue over an extended period of time
How can the overload principle be applied?
increasing resistance, time under tension, or repetitions
SAID principle is an extension of which law?
Wolff’s law - body systems adapt over time to the stresses placed on them (SAID = specific adaptation to imposed demands)
How quickly does detraining occur?
within 1-2 weeks after the cessation of resistance exercises
Factors that affect tension generated by a muscle:
- cross-section and size of muscle
- muscle architecture - fiber arrangement and length
- fiber-type distribution
- length-tension relationship
- recruitment of motor units
- frequency of firing units
- type of muscle contraction
- speed of muscle contraction (force-velocity relationship)
Factors contributing to muscle (local) fatigue:
- decrease in energy stores
- insufficient oxygen
- reduced sensitivity and availability of intracellular calcium
- build-up of H+
- reduced excitability at the NMJ or inhibitory effects of the CNS
Factors contributing to cardiopulmonary (general) fatigue:
- decrease in blood sugar level
- decrease in glycogen stores in muscle and liver
- depletion of potassium, especially in elderly
Neural adaptations to resistance training include:
- increased recruitment
- increased rate and synchronization of firing
- speculated to be caused by decreased inhibition and decreased sensitivity of the GTO
Determinants of resistance exercise:
- alignment of segments of body during exercise
- stabilization of proximal/distal to prevent substitution
- intensity (level of resistance)
- volume (reps/sets)
- exercise order
- frequency (per day/per week)
- rest interval (between sets/sessions)
- duration
- mode of exercise (type, position, arc of movement, energy system)
- velocity
- periodization or variation of intensity/volume
- integration of exercises into functional activities
When injured muscles are immobilized, type __ muscle fibers atrophy the fastest.
I (slow twitch)
_____ recovery is more effective than _______ recovery for neutralizing the effects of muscle fatigue.
Active; passive
During a maximum effort concentric muscle contraction, as the velocity of the muscle shortening increases, the force the muscle can generate _________.
decreases
This type of exercise stimulates co-contraction of agonists and antagonist.
closed-chain exercises
DeLorme Regimen
Determination of 10 RM:
10 reps @ 50% of the 10 RM
10 reps @ 75% of the 10 RM
10 reps @ 100% of the 10 RM
Oxford Regimen
Determination of 10 RM:
10 reps @ 100% of the 10 RM
10 reps @ 75% of the 10 RM
10 reps @ 50% of the 10 RM
DAPRE (Daily Adjustable Progressive Resistive Exercise)
Sets/Reps/Amount of Resistance: 1/10/50% of 6 RM 2/6/75% 6 RM 3/Max possible/100% of 6 RM 4/Max possible/100% adjusted working weight*
Functional Strength
ability of the neuromuscular system to produce, reduce, or control forces, contemplated or imposed, during functional activities in a smooth, coordinated manner
The most common adaptation to heavy resistance exercise?
increase in the maximum force-producing capacity of muscle (increase in muscle strength)
What two factors are primarily responsible for increase in muscle strength?
neural adaptations and increase in muscle fiber size