Transcript Slide 1

Adaptations to Aerobic and Anaerobic Training

CHAPTER 11

Overview

Adaptations to aerobic training

Adaptations to anaerobic training

Specificity of training and cross-training

Adaptations to Aerobic Training: Cardiorespiratory Endurance

• •

Cardiorespiratory endurance

– Ability to sustain prolonged, dynamic exercise – Improvements achieved through multisystem adaptations (cardiovascular, respiratory, muscle, metabolic)

Endurance training

–  Maximal endurance capacity =  VO 2max –  Submaximal endurance capacity • Lower HR at same submaximal exercise intensity • More related to competitive endurance performance

Figure 11.1

Adaptations to Aerobic Training: Major Cardiovascular Changes

• • • • • • •

Heart size Stroke volume Heart rate Cardiac output Blood flow Blood pressure Blood volume

Adaptations to Aerobic Training: Cardiovascular

O 2 transport system and Fick equation

– VO 2 = SV x HR x (a-v)O 2 difference –  VO 2max x  =  max SV x max HR max (a-v)O 2 difference •

Heart size

– With training, heart mass and LV volume  –  Target pulse rate (TPR)   SV cardiac hypertrophy  –  Plasma volume     SV LV volume   EDV – Volume loading effect

Figure 11.2

Adaptations to Aerobic Training: Cardiovascular

SV

after training

– Resting, submaximal, and maximal – Plasma volume    preload with training   EDV – Resting and submaximal HR    filling time   EDV with training –  LV mass with training   force of contraction – Attenuated  TPR with training   afterload •

SV adaptations to training

with age

Figure 11.3

Table 11.1

Adaptations to Aerobic Training: Cardiovascular

Resting HR

–  Markedly (~1 beat/min per week of training) –  Parasympathetic,  sympathetic activity in heart •

Submaximal HR

–  HR for same given absolute intensity – More noticeable at higher submaximal intensities •

Maximal HR

– No significant change with training –  With age

Figure 11.4

Adaptations to Aerobic Training: Cardiovascular

• • •

HR-SV interactions

– Does  HR   SV? Does  SV   HR?

– HR, SV interact to optimize cardiac output

HR recovery

– Faster recovery with training – Indirect index of cardiorespiratory fitness

Cardiac output (Q)

– Training creates little to no change at rest, submaximal exercise – Maximal Q  considerably (due to  SV)

Figure 11.5

Figure 11.6

Adaptations to Aerobic Training: Cardiovascular •

Blood flow to active muscle •

Capillarization, capillary recruitment

–  Capillary:fiber ratio –  Total cross-sectional area for capillary exchange

Blood flow to inactive regions •

Total blood volume

– Prevents any decrease in venous return as a result of more blood in capillaries

Table 11.2

Adaptations to Aerobic Training: Cardiovascular

Blood pressure

–  BP at given submaximal intensity –  Systolic BP,  diastolic BP at maximal intensity •

Blood volume: total volume

rapidly

–  Plasma volume via  and Na + plasma proteins, retention (all in first 2 weeks)  water –  Red blood cell volume (though hematocrit may  ) –  Plasma viscosity

Figure 11.7

Cardiovascular Adaptations to Chronic Endurance Exercise

Adaptations to Aerobic Training: Respiratory

• • •

Pulmonary ventilation

–  At given submaximal intensity –  At maximal intensity due to respiratory frequency  tidal volume and

Pulmonary diffusion

– Unchanged during rest and at submaximal intensity –  At maximal intensity due to  lung perfusion

Arterial-venous O 2

–  Due to  O 2

difference

extraction and active muscle blood flow –  O 2 extraction due to  oxidative capacity

Adaptations to Aerobic Training: Muscle

Fiber type

–  Size and number of type I fibers (type II  type I) – Type IIx may perform more like type IIa •

Capillary supply

–  Number of capillaries supplying each fiber – May be key factor in  VO 2max •

Myoglobin

–  Myoglobin content by 75 to 80% – Supports  oxidative capacity in muscle

Adaptations to Aerobic Training: Muscle

Mitochondrial function

–  Size and number – Magnitude of change depends on training volume •

Oxidative enzymes (SDH, citrate synthase)

–  Activity with training – Continue to increase even after VO 2max – Enhanced glycogen sparing plateaus

Figure 11.8a

Figure 11.8b

Figure 11.8c

Figure 11.9

Adaptations to Aerobic Training: Muscle

High-intensity interval training (HIT): time efficient way to induce many adaptations normally associated with endurance training

Mitochondrial enzyme cytochrome oxidase (COX)

same after HIT versus traditional moderate-intensity endurance training

Effects of HIT Versus Endurance Training on COX Activity

Adaptations to Aerobic Training: Metabolic

Lactate threshold

–  –  To higher percent of VO 2max Lactate production,  lactate clearance – Allows higher intensity without lactate accumulation •

Respiratory exchange ratio (RER)

–  At both absolute and relative submaximal intensities –  Dependent on fat,  dependent on glucose

Figure 11.10

Adaptations to Aerobic Training: Metabolic

Resting and submaximal VO 2

– Resting VO 2 unchanged with training – Submaximal VO 2 training unchanged or  slightly with •

Maximal VO 2 (VO 2max )

– Best indicator of cardiorespiratory fitness –  Substantially with training (15-20%) –  Due to  cardiac output and capillary density

Table 11.3

Table 11.3

(continued)

Adaptations to Aerobic Training: Metabolic

Long-term improvement

– Highest possible VO 2max achieved after 12 to 18 months – Performance continues to  after VO 2max plateaus because lactate threshold continues to  with training •

Individual responses dictated by

– Training status and pretraining VO 2max – Heredity

Figure 11.11

Adaptations to Aerobic Training: Metabolic

Training status and pretraining VO 2max

– Relative improvement depends on fitness – The more sedentary the individual, the greater the  – The more fit the individual, the smaller the  •

Heredity

– Finite VO 2max alters VO 2max range determined by genetics, training within that range – Identical twin’s VO 2max more similar than fraternal’s – Accounts for 25 to 50% of variance in VO 2max

Figure 11.12

Adaptations to Aerobic Training: Metabolic

• •

Sex

– Untrained female VO 2max – Trained female VO 2max < untrained male VO closer to male VO 2max 2max

High versus low responders

– Genetically determined variation in VO 2max training stimulus and compliance for same – Accounts for tremendous variation in training outcomes for given training conditions

Table 11.4

Table 11.4

(continued)

Figure 11.13

Figure 11.14

Adaptations to Aerobic Training: Fatigue Across Sports

Endurance training critical for endurance based events

Endurance training important for non endurance-based sports, too

All athletes benefit from maximizing cardiorespiratory endurance

Adaptations to Anaerobic Training

Changes in anaerobic power and capacity

– Wingate anaerobic test closest to gold standard for anaerobic power test – Anaerobic power and capacity  with training •

Adaptations in muscle

–  In type IIa, IIx cross-sectional area –  In type I cross-sectional area (lesser extent) –  Percent of type I fibers,  percent of type II

Adaptations to Anaerobic Training

ATP-PCr system

– Little enzymatic change with training – ATP-PCr system-specific training  strength  •

Glycolytic system

–  In key glycolytic enzyme activity with training (phosphorylase, PFK, LDH, hexokinase) – However, performance gains from  in strength

Figure 11.15

Figure 11.16

Specificity of Training and Cross-Training

Specificity of training

– VO 2max activity substantially higher in athlete’s sport-specific – Likely due to individual muscle group adaptations •

Cross-training

– Training different fitness components at once

or

training for more than one sport at once – Strength benefits blunted by endurance training – Endurance benefits

not

blunted by strength training

Figure 11.17

Table 11.5