NSCA Chapter 5: Resistance Training AdaptationsTessa Acay

In this chapter (overview) ….

Explains general adaptations that result from progressive overwork

Neurological

Muscle and connective tissue

Skeletal

Metabolic

Hormonal

Cardiovascular

Body composition changes

Resistance training is very personal and highly specific (the impact that gender, age , genetics have )

Overtraining and detraining and how to prevent.

Resistance Training

Physical training that utilizes isometric, isotonic, or isokinetic exercise to strengthen or develop the muscles.

Training of this kind helps build muscular and nervous system

Basic Adaptations to Resistance Exercise

Acute Adaptations Changes that occur in the

body during and shorty after an exercise

Referred to as “responses” to exercise

Example: fuel substrates in muscle such as creatine phosphate can become depleted during an exercise

Chronic Adaptations Referred to as changes in the

body that occur after repeated training

Persist long after a training session is over

Example: long-term resistance results in increases in muscle mass, which largely drive the increase in force production capability of the muscle

Acute Responses to Resistance Training

Neurological Changes Performance resistance training requires activation of

the skeletal muscle. Activation involves: generation on the muscle cell

membrane via acetylcholine release from the alpha motor neuron that stimulates a particular muscle cell

Size of (Electromyography) EMG caries as a function of muscle force output but is also affected by fatigue and muscle fiber composition

Neurological Changes Rate coding refers to control of motor unit firing rate(number

of action potentials per unit of time) Small muscles (hand) that require very precise motor control

achieve full recruitment relatively low percentages of max. force output

Motor unit recruitment refers to the process in which tasks that require more force involves activation of more motor units

Recruitment of motor units for force production follows the size principle, meaning that smaller motor units are recruited at lower force levels and large motor units are required at higher force levels

Muscular Changes

Glycogen breakdown is an important factor in the supply of energy for this type of training

Over 80% of the ATP production during body building comes from glycoses

Glycogen levels decrease after high intensity resistance training

Metabolites accumulate and fuel substrates are depleted Clients need to include adequate carbohydrate in their

diets

Endocrine Changes

Hormones are blood-borne molecules Protein/peptide hormones: growth and insulin Steroid hormones : testosterone and estrogen Anabolic hormones such as insulin and testosterone

stimulate growth process Catabolic hormones such as cortisol function to use

tissue degradation to help maintain homeostasis of variables such as blood glucose

Chronic Adaptations to Resistance Training

Chronic Adaptations to Resistance Training

Neurological Changes

Increases in strength occur rapidly during the early stages of a resistance program and that they are larger than can be accounted for by changes in muscle size- attributed to so-called neural factors

Dominant in the first two months of training

Free weight exercises, balancing, efficiency of movement in order to be performed well-improved skill

Cont.

Motor recruitment and firing rate is also the primary reason for strength gains

Untrained individuals are unable to activate all the motor units that are available

Co-contraction: the simultaneous activation of an agonist and an antagonist during a motor task

Example is during a knee exercise the quadriceps muscles are agonists (prime movers) while the hamstrings are serve as the antagonist

Decreased co-contraction would decrease the antagonist torque that must be overcome during contraction, enhancing strength

Muscle Tissue Changes

Hypertrophy: an increase in muscle size to long-term resistance training

Training results in increase in cross-sectional area of both Type I and II muscle fibers

This results in increased force and power production capability

Hyperplasia: the increase in number of muscle fibers (found only to occur in animal models)

Skeletal Changes Bones serve as a depot for important minerals

(calcium) Osteoporosis: consequence of long term net

demineralization of bone Most research focused on women (postmenopausal)

Related to resistant training and bone tissue being affected by strain

Bone formation declines because hormones like estrogen decline after

The greater the bone mass prior to menopause the less severe consequences of loss of bone mass

Resistance training may lead to decreased risk for osteoporosis, fractures, and falls later in life ( positive effect on bone tissue)

Metabolic Changes

Training changes metabolism

Adaptions are complicated

hypertrophy will dilute enzyme and substrate levels

so that changes in the absolute levels may result in no change of relative levels

Cardiovascular Changes

Increasing cardiorespiratory endurance capabilities requires aerobic endurance-specific training to achieve optimal results

Can augment cardiovascular endurance performance and running efficiency by increasing muscle strength and power

Detraining and Overtraining

Detraining Refers to the physiological and

performance adaptation that occur when an individual ceases an exercise training program

Overtraining The symptoms of overtraining from

resistance Exercise are:

Plateau followed by decrease of strength gains

Sleep disturbances

Decrease in lean body mass

DECREASED APPETITE

A cold that wont go away

Mood changes

Excessive muscle soreness

Lost of interest in the training program

Study Question #1: Which of the following is most likely to occur during a set of 10 repetitions at 75% of the 1RM for the squat exercise?

a) Motor unit recruitment increasesb) Rate coding decreasesc) Muscle pH increasesd) ATP stores increase

Explanation: A) Motor unit recruitment increases (pg 84)

Motor unit recruitment: the measure of how many motor neurons are

Also the measurement of how many muscle fibers of that muscle are activated

The higher the recruitment, the stronger the muscle contraction will be

Study question #2:Which of the following is most responsible for the strength gain a client would experience following 3 weeks of a beginning resistance training program?

a)Muscle hypertrophy

b)Muscle hyperplasia

c)Increased co-contraction

d)Improved skill in performing the exercise

Explanation: D) improved skill in the exercise (pg 84 &85))

Resistance training: any exercise that causes the muscles to contract against an external resistance with the expectation of increases in strength, tone, mass, and or endurance

After multiple reps of resistance training you will become stronger and more toned in the exercise which will allow you to perform the exercise better

Q#3:Which of the following are the most influential age-related changes that may decrease a client’s ability to exhibit muscular strength?

I. decreased ability to produce force rapidly

II. Decreased bone density

III. Decreased muscle mass

IV. Decreased muscle glycogen stores

A. I and III

B. II and IV

C. I and IV only

D.II and III only

Explanation: A) I and III only (pg91)

Muscular strength is the ability of a muscle to exert a maximal or near maximal force against an object

Both prevent the muscle from exerting strong forces because both muscle mass and the ability to produce force rapidly are necessary

Need a good diet and the repetitions for the exercise

Q#4: All of the following are symptoms of overtraining from resistance exercise EXCEPT:

A) increased hunger and thirst B) inconsistent or interrupted sleep C) non-purposeful decreases in lean body mass D) leveled-off improvements or losses in muscular

strength

Explanation A) Increased hunger and thirst

The symptoms of overtraining from resistance Exercise are:

Plateau followed by decrease of strength gains

Sleep disturbances

Decrease in lean body mass

DECREASED APPETITE (exact opposite of this sysptom)

A cold that wont go away

Mood changes

Excessive muscle soreness

Lost of interest in the training program

Applied Knowledge question: Complete the following chart to describe two ways the body's system adapt to chronic participation in a resistance training program

System Two Adaptations

Nervous EMG amplitude increases, motor units recruited increases

Muscular Ammonia levels increase CP concentration depletes

Skeletal Connective tissue strength increases, body/density mass increases

Metabolic Phosphagen system does not increase in resistances training concentration of ATP, Glycolytic enzymes are not found in high resistance training

Cardiovascular Endurance increases while development more oxygen consumption, more aerobic endurance activities increase cardiorespiratory endurance