Sports and Exercise Physiology

Question 1

Strength of a muscle is determined mainly by its ___

Answer 1

Size

Question 2

Maximal contractile force is computed as

Answer 2

muscle size in squared cm multiplied by 3.5

Question 3

The holding strength of muscles is about ____ percent (greater or lesser?) than the contractile strength.

Answer 3

40

greater

Question 4

This is the amount of force applied by the muscle multiplied by the distance over which the force is applied

Answer 4

Mechanical work

Question 5

This is a measure of the total amount of work that the muscle performs in a unit period of time.

Answer 5

Power

Question 6

At maximal load, the muscle cannot lift the load and hence cannot shorten. This is known as _________ velocity

Answer 6

zero velocity

Question 7

The maximal isometric tension (i.e., force at which shortening
velocity is zero) is proportional to the:

Answer 7

number of active cross-bridges between actin and myosin (greatest with fast-twitch fibers

Question 8

The maximal rate of work was done at a ________ load (namely, when the force of contraction was approximately 30% of the maximal tetanic tension)

Answer 8

submaximal

Question 9

The velocity at which a muscle shortens is strongly dependent
on the:

Answer 9

amount of force that the muscle must develop

Question 10

____ corresponds to the maximal cycling rate of the cross-bridges that occurs with the absence of any load

Answer 10

Maximal shortening velocity (V0)

Question 11

Contraction in which muscle length is held constant, and the force generated during the contraction is then measured.

Answer 11

Isometric

Question 12

Contraction in which the force (or tone) is held constant, and the change in length of the muscle is then measured

Answer 12

Isotonic

Question 13

When a muscle at rest is stretched, it resists stretch by a force that increases slowly at first and then more rapidly as the extent of stretch increases. This purely passive property is due to the _____ of the muscle tissue.

Answer 13

elasticity

Question 14

Contractile force increases as muscle length is increased up to a point known as:

Answer 14

Optimal length (Lo)

Question 15

T/F: As the muscle is stretched beyond LO, contractile force decreases.

Answer 15

T

Question 16

The adaptive response of skeletal muscle fibers to endurance exercise is mainly the result of:

Answer 16

an increase in the oxidative metabolic capacity of the motor units involved

Question 17

Regular maximal-strength exercise, such as weightlifting, induces the synthesis of more ________ and hence hypertrophy of the active muscle cells

Answer 17

myofibrils

Question 18

The prime factors that cause the pain during DOMS are _________ and ________ from injury to muscle cells, most commonly near the myotendinous junction.

Answer 18

swelling and inflammation

Question 19

Type of motor units are affected more in the development of DOMS

Answer 19

Type II than type I motor units because the maximal force is highest in large cells

Question 20

The source of energy actually used to cause muscle contraction is:

Answer 20

adenosine triphosphate (ATP)

Question 21

Each high-energy bonds of ATP contains how much calories of energy?

Answer 21

7300 cal

Question 22

The high-energy phosphate bond of phosphocreatine has how much calories of energy?

Answer 22

10,300

- higher than the bond of ATP: 10,300 calories per mole compared with 7300 for the ATP bond.

Question 23

The combined amounts of cell ATP and cell phosphocreatine are called the:

Answer 23

phosphagen energy system

Question 24

Which energy system is used for short burst of muscle power?

Answer 24

phosphagen energy system