Chapter 14: The Physiology of Resistance Training

Resistance training-induced shifts in muscle fiber types are less prominent than observed with endurance training-induced transformations because all of the change in fiber type is a movement from _____ fibers.

type IIx to type IIa

Which of the following happens within two weeks after beginning resistance training?

Muscular strength increases without an increase in muscle fiber size

Identify the true statements about the impact of the mechanisms responsible for the impairment of strength development during concurrent strength and endurance training. (Check all that apply.)

-In theory, overtraining could contribute to the inability to attain optimal strength gains during concurrent strength and endurance training. -Some investigators predict that concurrent training may impair neural adaptations to resistance training.

Identify the true statements about the impact of resistance training on muscle growth. (Check all that apply.)

-Several endogenous hormones such as testosterone, insulin-like growth factor-1 (IGF-1) have the potential to increase muscle protein synthesis. -Resistance training-induced increases in protein synthesis is likely due to the intrinsic signaling mechanisms within muscle fibers.

The stoppage of resistance training results in ______.

a loss of muscular strength

In the context of the process involved in executing a muscular contraction, how much muscular force is developed is dependent upon _____

the level of inhibitory signaling to the central nervous system

Resistance training could improve muscular strength by _____.

reducing antagonist co-activation during a movement

In the context of resistance training-induced muscle growth, postexercise protein synthesis _____.

remains elevated for a longer period in untrained individuals

In the context of resistance training, identify the true statements about hypertrophy. (Check all that apply.)

-Hypertrophy is likely the primary way to increase muscle mass following long-term strength training. -Hypertrophy refers to an increase in muscle fiber size.

Which of the following are true about the impact of increased oxidative stress? (Check all that apply.)

-It decreases muscle protein synthesis. -It rapidly activates enzymes (proteases) that break down muscle proteins.

_____ refers to the observation that if one limb engages in resistance training, muscular strength increases in the untrained (contralateral) limb

Cross education

Prolonged periods of resistance training results in a _____ in muscle fiber types within the trained muscles.

fast-to-slow shift

Independent of resistance exercise, the branched chain amino _____ can activate the mechanistic target of rapamycin (mTOR) and promote small increases in muscle protein synthesis.

leucine

True or false: The quantity of skeletal muscle mass differs widely between individuals and this difference is largely due to inherited traits.

True The quantity of skeletal muscle mass differs widely between individuals and this difference is largely due to inherited traits (i.e., genetic differences between individuals). Indeed, it is predicted that the 80% of the differences in muscle mass between individuals can be explained by genetic variation.

Rank the steps in the process involved in executing a muscular contraction in the order of their occurrence. (Place the first step at the top.)

1. a neural message is forwarded to the motor cortex 2. the message is dispatched to the brain stem and relayed to the spinal cord 3. the excitatory neural message depolarizes motor neurons 4. Waves of depolarization are sent down to the axon to the muscle fibers contained in the motor unit

_____ refers to an increase in the total number of muscle fibers within a specific muscle (e.g., biceps brachii).

Hyperplasia

The changes observed within two weeks after beginning resistance training indicate that _____

increases in strength can be accomplished by changes in the nervous system without an increase in muscle mass

A protein kinase called the _____ is the major regulator of protein synthesis and muscle size. When activated it promotes protein synthesis by increasing translation, which results in increased protein synthesis.

mechanistic target of rapamycin (mTOR)

In contrast to detraining in endurance training, detraining in resistance training _____.

occurs at a slower rate

Muscular strength refers to the maximal force that a muscle or muscle group can generate and is commonly expressed as the ___ ___ ___ or 1-RM, which is the maximum load that can be moved through a full range of motion.

one repetition maximum

A key regulator of disuse muscle atrophy is the _____.

production of free radicals in the inactive muscle fibers

A 1-RM or one-repetition maximum is _____

the maximal amount of weight that a person can lift for one repetition

Match the type of muscles involved in resistance training (in the left column) with their descriptions (in the right column).

-Agonist = Muscle that results in movement of a limb in the desired direction -Antagonist = Opposes the movement of a limb in the desired direction

Which of the following can cause the activation of mTOR in resistance training? (Check all that apply.)

-An increase in muscle levels of phosphatidic acid (PA) -Elimination of tuberous sclerosis complex 2 (TSC2) blockade of Rheb

Identify the true statements about the impact of endurance exercise training. (Check all that apply.)

-Endurance exercise training increases the oxidative capacity in the trained muscle fibers. -Endurance exercise training promotes the formation of new capillaries around the trained muscle fibers.

Which of the following are true about the events leading to resistance training-induced muscle growth? (Check all that apply.)

-Exercise-induced increase in muscle protein synthesis is largely due to an increase in the amount of protein synthesized per molecule of mRNA. -Within the first several workouts of a resistance training program, ribosomal abundance increases in the muscle.

Which of the following statements are true about the impact of resistance training? (Check all that apply.)

-It has a positive impact on the strength of connective tissue. -It increases the size and strength of both tendons and ligaments.

Identify the true statements about the impact of resistance training. (Check all that apply.)

-It increases bone mineral content. -It improves muscle antioxidant capacity.

Which of the following statements are true about the magnitude of resistance training-induced hypertrophy? (Check all that apply.)

-People can be categorized into three groups based upon their level of muscle hypertrophy following resistance training. -The degree of exercise-induced increases in muscle protein synthesis varies significantly between individuals.

Which of the following can promote muscle atrophy? (Check all that apply.)

-Space flight -Prolonged bed rest

Which of the following statements are true about the impact of resistance training on muscle growth? (Check all that apply.)

-The addition of myonuclei to growing skeletal muscle fibers appears to be essential for optimal fiber hypertrophy in response to resistance training. -The addition of new nuclei to the muscle is required to increase fiber size after the initial growth that occurs early in resistance training.

Identify the factors that contribute to the magnitude of increased neural drive due to resistance training. (Check all that apply.)

-The firing rate of motor neuron -The total number of motor neurons activated -Neural transmission across the neuromuscular junction

Which of the following statements are true about hypertrophy in the context of resistance training? (Check all that apply.)

-Weight training elicits a greater degree of hypertrophy in type II fibers than in type I fibers. -Skeletal muscle hypertrophy results in increased strength.

Rank the time-dependent changes in resistance exercise-induced signaling in skeletal muscles in the order of their occurrence. (Place the first change at the top.) Drag and drop application.

1. muscles levels of activated Rheb and phosphatidic acid begin to rise 2.mTOR activation begins 3. Muscle protein synthesis increases

In the context of the impact of the protein synthesis on the impairment of strength development during concurrent strength and endurance training, which of the following is true?

Concurrent bouts of resistance and endurance exercise training could result in impaired protein synthesis following resistance exercise training

True or false: Neural adaptations that arise from strength training are similar to those that occur with endurance exercise training.

False

In the context of resistance training, identify a true statement about hyperplasia.

It is likely that the contribution of hyperplasia to training-induced muscle mass is small.

_____ is defined as a reduction in the cross-sectional area of muscle fibers resulting in a decrease in muscle mass.

Muscle atrophy

True or false: Whether resistance training improves muscle oxidative properties is likely dependent upon the duration and volume of the training period.

True. Studies that used long-duration resistance training programs (weeks to months) with high frequencies of training (3 days/week) and high volume (i.e., high number of repetitions) of exercise consistently report small improvements in both muscle oxidative capacity and capillarization around fibers. Therefore, whether resistance training improves muscle oxidative properties is likely dependent upon the duration and volume of the training period.

Muscles receive a neural activation signal from motor neurons located in the spinal cord. This neural signal is referred to as _____ _____

neural drive

A single bout of resistance exercise _____.

promotes an increase in muscle protein synthesis following exercise

Exercise-induced increases in both muscle hypertrophy and strength is a relatively slow process because _____.

protein synthesis must exceed protein breakdown for three or more weeks to achieve significant muscle growth