Exercise Physiology Chapter 4 Review

The .... does not fall instantaneously from the steady-state value measured during the exercise to the resting-state value that can be associated with standing by a treadmill.

The .... does not fall instantaneously from the steady-state value measured during the exercise to the resting-state value that can be associated with standing by a treadmill.

metabolic rate

The rapid portion

It is represented by the steep decline in oxygen uptake following exercise.

The slow portion

It is represented by the slow decrease in oxygen consumption across time following exercise.

During a three-minute bout of exercise, the ATP production from ... was highest in the first minute of exercise.

phosphocreatine (PC)

The process of glucose synthesis from non-carbohydrate sources is known as ...?

gluconeogenesis

Which of the following factors contribute to the EPOC (excess post-exercise oxygen consumption)?

elevated body temperature, elevated hormone levels

Identify the reasons why excess post-exercise oxygen consumption (EPOC) is greater during high-intensity exercise when compared to moderate-intensity exercise.

higher blood lactate levels, and depletion of phosphocreatine to a greater extent

The ... portion of excess post-exercise oxygen consumption (EPOC) immediately follows an exercise

rapid

The rapid portion of EPOC represents the oxygen required to resynthesize stored ... and replace tissue stores of oxygen.

ATP and PC

Compared to moderate-intensity exercise, the total EPOC is greater following very heavy exercise because epinephrine and norepinephrine levels are?

higher

The energy to perform a short-term exercise of high intensity is produced primarily from?

anaerobic metabolic pathways

In the context of an incremental exercise test, identify a true statement about oxygen uptake.

It increases systematically with work rate until VO2 max is reached.

A factor that influences VO2 max depends on the muscle's ability to?

take up oxygen and produce ATP aerobically

The maximal capacity to transport and utilize oxygen during exercise is known as ?

maximal oxygen uptake/ consumption

Slow muscle fibers contain an LDH isozyme that promotes the formation of ?

pyruvate

Continuous exercise at a high relative work rate greater than ... results in a slow rise in oxygen uptake across time. Therefore, a steady state cannot be maintained during such an exercise.

75% VO2 max

During steady-state conditions, the VCO/Oz ratio is called the respiratory quotient, as it is thought to reflect the CO2 production and Oz consumption by the ... of the active muscles.

mitochondria

The maximum ability of the cardiorespiratory system to deliver oxygen to the ... is known to influence VO2 max.

contracting muscle

The subject should reach a steady state for _____ to be used as an estimate of substrate utilization as only during the steady-state are VCO2 and VO2 reflective of O2 uptake and CO2 production in the tissues.

respiratory exchange ratio (R)

As the exercise intensity increases, blood levels of ____ begin to rise in an exponential fashion.

lactate

Fat oxidation

0.7

Carbohydrate oxidation

1

___ contribute to less than 2% of the substrate used during exercise of less than one hour's duration.

Proteins

As the exercise intensity increases above the crossover point, a progressive shift occurs from _____ metabolism.

fat to carbohydrate

Identify the term often defined as the exercise intensity (or oxygen consumption) at which a specific blood lactate concentration is reached..

onset of blood lactate accumulation

High levels of epinephrine increase _____ activity, which causes an increase in muscle glycogen breakdown. This leads to an increased rate of glycolysis and lactate production.

phosphorylase

Whether fat or carbohydrate is the primary substrate during work is determined by several factors. Identify those factors.

the duration of exercise, the intensity of exercise, and diet

Which of the following hormones stimulate lipase activity?

epinephrine, norepinephrine, glucagon

Fast muscle fibers have an abundance of ___ that make them better equipped to metabolize carbohydrates than fats.

glycolytic enzymes

Depletion of muscle and blood carbohydrate stores results in ___

muscle fatigue

As exercise intensity increases, there is a progressive rise in blood levels of ?

epinephrine

Depletion of available muscle carbohydrate reduces the rate of glycolysis, and therefore the concentration of ___ in the muscle is also reduced. This lowers ATP production, and in turn, increases muscular fatigue.

pyruvate

When _____ stores are depleted in the body, the rate at which fat is metabolized is also reduced.

carbohydrate

Muscle _____ is the primary carbohydrate energy source during high-intensity exercise.

glycogen

During prolonged exercise of more than two hours, the muscle and liver stores of ___ can reach very low levels.

glycogen

A reduction in glycogen stores also causes a diminished rate of ATP production from _____ metabolism which specifically requires oxidation via the Kreb's cycle.

fat

In the liver, the amino acid ___ can be converted to glucose and returned via the blood to skeletal muscle to be utilized as a substrate for producing energy.

alanine

Muscle glycogen stores in the body provide a direct source of carbohydrate for muscle energy metabolism.

True

During prolonged moderate-intensity exercise of more than 2 hours, enzymes capable of degrading muscle proteins called ___ activate?

proteases

Which of the following energy sources play a greater role during low-intensity exercise?

blood glucose

Most fat in the body is stored in the form of ___ in adipocytes.

triglycerides

During exercise, the skeletal muscle can directly metabolize ___ amino acids such as valine, leucine, and isoleucine to produce ATP.

branched chain

The activation of enzymes capable of degrading muscle proteins during prolonged moderate-intensity exercise appears to be due to exercise-induced increases in ___ levels within muscle fibers.

calcium

The primary source of fat as an energy source during low-intensity exercise is plasma ___?

free fatty acids