NSCA Chapter 5: Resistance Training Adaptations Tessa 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 Chronic 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 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 Refers to the physiological and performance adaptation that occur when an individual ceases an exercise training program 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

Motor unit recruitment increases Rate coding decreases 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? Motor unit recruitment increases Rate coding decreases Muscle pH increases 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

I. decreased ability to produce force rapidly 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

EMG amplitude increases, motor units recruited increases Muscular 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