Chapter 13
The Physiology of Training
Effect on VO_{2 MAX}, Performance, Homeostasis, and Strength

EXERCISE PHYSIOLOGY

Exercise
A Challenge to Homeostasis

Principles of Training

•Overload

–Training effect occurs when a system is exercised at a level _____________________ which it is _____________________ accustomed

•Specificity

–Training effect _____________________ _____________________ involved

–Type of exercise

•Reversibility

–_____________________ _____________________ when overload is removed

Research Designs to
Study Training

•_____________________ studies

–Examine groups of _____________________ physical activity at one time

–Record differences _____________________ groups

•_____________________ studies

–Examine groups before and after training

–Record changes over time in the groups

Endurance Training and VO_2max

•Training to increase VO_2max

–Large muscle groups, dynamic activity

–_____________________ min, _____________________ times/week, 50-85% VO_2max

•Expected increases in VO_2max

–_____________________ (average) _____________________ (strenuous or prolonged training)

–Greater increase in highly deconditioned or diseased subjects

•Genetic predisposition

–Accounts for _____________________ VO_2max

Calculation of VO_2max

____________________________________________________

Improvements in VO_2max

–50% due to ________

–50% due to ________

Differences in VO_2max in normal subjects

–Due to differences in __________

Stroke Volume
(equal to difference in _________ and __________)
and Increased VO_2max

•Increased SV_max

–_____________________ - End Diastolic Vol. (EDV)

• Plasma volume

• Venous return - Due to Ventricle Size, Pre load.

• Ventricular V olume

–_____________________ (TPR) - Decreased Resistance to Blood Flow

•¯ Arterial constriction

• Maximal muscle blood flow with no change in mean arterial pressure

– Contractility ( Force of Contration)

Factors Increasing Stroke Volume

_____________________ e and _____________________

Improved ability of the muscle to extract oxygen from the blood

– Muscle blood flow

– Capillary density

– _____________________

Increased a-vO₂ difference accounts for ____________ of increased VO_2max

Factors Causing Increased VO_2max

_____________________ and VO_2max

•Decrease in VO_2max with cessation of training

–¯ SV_max

–¯ maximal a-vO₂ difference

•Opposite of training effect

Endurance Training
Effects on Performance

•Improved performance following endurance training

•Structural and biochemical changes in muscle

–_____________________ number

•_____________________ activity

–_____________________ density

Structural and Biochemical Adaptations to Endurance Training

•_____________________ number

•_____________________ enzymes

–Krebs cycle (citrate synthase)

–Fatty acid (b-oxidation) cycle

–Electron transport chain

•_____________________ shuttling system

•Change in Lactate Dehydrogenase (LDH)

–Lactate formation occurs when there is an accumulation of NADH and pyruvate in the cytoplasm of the cell where LDH is present.

•Adaptations quickly lost with detraining

Detraining
Changes in _____________________

About ____________ of the increase in mitochondrial content was lost after _________ week of detraining

•All of the adaptations were lost after ___________ weeks of detraining

•It took ____________ weeks of _______________ to regain the adaptations lost in the ______ week of detraining

Training/Detraining Mitochondrial Changes

Effect Intensity and Duration on Mitochondrial Enzymes

•_________________ (CS)

–Marker of mitochondrial oxidative capacity

–Light to moderate exercise training

•Increased CS in high oxidative fibers

(Type I and IIa)

–Strenuous exercise training

•Increased CS in low oxidative fibers

(Type IIb)

Changes in CS Activity Due to Different Training Programs
Question: What does this tell us about metabolism and weight control?

___________________ Number and
___________________ Concentration on VO₂

•[ADP] stimulates mitochondrial ATP production

•Increased mitochondrial number following training

–________________ [ADP] needed to increase ATP production and VO₂

Mitochondrial Number and ADP Concentration on VO₂

Biochemical Adaptations
and Oxygen Deficit

•Oxygen deficit is _____________________ following training

–Same VO₂ at lower [ADP]

–Energy requirement ____________ be met by oxidative ___________ production at the _____________ of exercise

•Results in _______________ lactic acid formation and ___________ PC depletion

Effects of Endurance Training on O₂ Deficit

Biochemical Changes
and FFA Oxidation

•_____________________ mitochondrial number and capillary density

–_____________________ capacity to transport FFA from plasma to cytoplasm to mitochondria

•_____________________ enzymes of b-oxidation

–_____________________ rate of acetyl CoA formation

•_____________________ FFA oxidation

–Spares muscle glycogen and blood glucose

FFA Oxidation and
Glucose-Sparing

Blood Lactate Concentration

•Balance between lactate production and removal

•Lactate production during exercise

–NADH, pyruvate, and LDH in the cytoplasm

•Blood pH affected by blood lactate concentration

Mitochondrial and Biochemical Adaptations and Blood pH

Blood Lactate Concentration

Biochemical Adaptations
and Lactate Removal

Links Between Muscle and Systemic Physiology

•Biochemical adaptations to training influence the physiological response to exercise

–Sympathetic nervous system (_____________________ E/NE)

–Cardiorespiratory system (_____________________ HR, _____________________ ventilation)

•Due to:

–Reduction in “_____________________” from muscle _____________________

–Reduced number of _____________________ recruited

•Demonstrated in one leg training studies

One Leg Training Study

Physiological Effects of Strength Training

•Strength training results in increased muscle _____________________ and _____________________

•Neural factors

–_____________________ ability to activate _____________________ units

–Strength gains in initial 8-20 weeks

•Muscular enlargement

–Mainly due to enlargement of fibers (_____________________)

–Long-term strength training

_____________________ and _____________________ Adaptations
to _____________________ Training

Chapter 13
The Physiology of Training
Effect on VO_{2 MAX}, Performance, Homeostasis, and Strength