Adaptations to Aerobic and

Anaerobic Training

Adaptations to Aerobic Training:Adaptations to Aerobic Training:Cardiorespiratory EnduranceCardiorespiratory Endurance

• Cardiorespiratory endurance– Ability to sustain prolonged, dynamic exercise– Improvements achieved through multisystem

adaptations (cardiovascular, respiratory, muscle, metabolic)

• Endurance training– Maximal endurance capacity = VO2max

– Submaximal endurance capacity• Lower HR at same submaximal exercise intensity• More related to competitive endurance

performance

Figure 11.1Figure 11.1

Adaptations to Aerobic Training:Adaptations to Aerobic Training:Major Cardiovascular ChangesMajor Cardiovascular Changes

• Heart size

• Stroke volume

• Heart rate

• Cardiac output

• Blood flow

• Blood pressure

• Blood volume

Adaptations to Aerobic Training:Adaptations to Aerobic Training:CardiovascularCardiovascular

• O2 transport system and Fick equation

– VO2 = SV x HR x (a-v)O2 difference

– VO2max = max SV x max HR x max (a-v)O2 difference

• Heart size– With training, heart mass and LV volume

– Target pulse rate (TPR) cardiac hypertrophy SV

– Plasma volume LV volume EDV SV

– Volume loading effect

Adaptations to Aerobic Training:Adaptations to Aerobic Training:CardiovascularCardiovascular

• SV after training– Resting, submaximal, and maximal– Plasma volume with training EDV

preload– Resting and submaximal HR with training

filling time EDV

– LV mass with training force of contraction– Attenuated TPR with training afterload

• SV adaptations to training with age

Figure 11.3Figure 11.3

Table 11.1Table 11.1

Adaptations to Aerobic Training:Adaptations to Aerobic Training:CardiovascularCardiovascular

• 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 11.4Figure 11.4

Adaptations to Aerobic Training:Adaptations to Aerobic Training:CardiovascularCardiovascular

• 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 11.5Figure 11.5

Figure 11.6Figure 11.6

Adaptations to Aerobic Training:Adaptations to Aerobic Training:CardiovascularCardiovascular

• 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

Adaptations to Aerobic Training:Adaptations to Aerobic Training:CardiovascularCardiovascular

• Blood pressure– BP at given submaximal intensity

– Systolic BP, diastolic BP at maximal intensity

• Blood volume: total volume rapidly– Plasma volume via plasma proteins, water

and Na+ retention (all in first 2 weeks)

– Red blood cell volume (though hematocrit may )

– Plasma viscosity

Cardiovascular Adaptations to Cardiovascular Adaptations to Chronic Endurance ExerciseChronic Endurance Exercise

Adaptations to Aerobic Training:Adaptations to Aerobic Training:RespiratoryRespiratory

• Pulmonary ventilation– At given submaximal intensity

– At maximal intensity due to tidal volume and respiratory frequency

• Pulmonary diffusion– Unchanged during rest and at submaximal intensity

– At maximal intensity due to lung perfusion

• Arterial-venous O2 difference

– Due to O2 extraction and active muscle blood flow

– O2 extraction due to oxidative capacity

Adaptations to Aerobic Training:Adaptations to Aerobic Training:MuscleMuscle

• 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 VO2max

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

Adaptations to Aerobic Training:Adaptations to Aerobic Training:MuscleMuscle

• 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 VO2max plateaus

– Enhanced glycogen sparing

Adaptations to Aerobic Training:Adaptations to Aerobic Training:MuscleMuscle

• 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

Adaptations to Aerobic Training:Adaptations to Aerobic Training:MetabolicMetabolic

• Lactate threshold– To higher percent of VO2max

– 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 11.10Figure 11.10

Adaptations to Aerobic Training:Adaptations to Aerobic Training:MetabolicMetabolic

• Resting and submaximal VO2

– Resting VO2 unchanged with training

– Submaximal VO2 unchanged or slightly with training

• Maximal VO2 (VO2max)– Best indicator of cardiorespiratory fitness

– Substantially with training (15-20%)

– Due to cardiac output and capillary density

Table 11.3Table 11.3

Table 11.3 Table 11.3 (continued)(continued)

Adaptations to Aerobic Training:Adaptations to Aerobic Training:MetabolicMetabolic

• Long-term improvement– Highest possible VO2max achieved after 12 to 18

months

– Performance continues to after VO2max plateaus because lactate threshold continues to with training

• Individual responses dictated by– Training status and pretraining VO2max

– Heredity

Adaptations to Aerobic Training:Adaptations to Aerobic Training:MetabolicMetabolic

• Training status and pretraining VO2max

– Relative improvement depends on fitness

– The more sedentary the individual, the greater the – The more fit the individual, the smaller the

• Heredity– Finite VO2max range determined by genetics, training

alters VO2max within that range

– Identical twin’s VO2max more similar than fraternal’s

– Accounts for 25 to 50% of variance in VO2max

Adaptations to Aerobic Training:Adaptations to Aerobic Training:MetabolicMetabolic

• Sex– Untrained female VO2max < untrained male VO2max

– Trained female VO2max closer to male VO2max

• High versus low responders– Genetically determined variation in VO2max for same

training stimulus and compliance– Accounts for tremendous variation in training

outcomes for given training conditions

Adaptations to Aerobic Training:Adaptations to Aerobic Training:Fatigue Across SportsFatigue 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 TrainingAdaptations 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 TrainingAdaptations 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

Specificity of Training Specificity of Training and Cross-Trainingand Cross-Training

• Specificity of training– VO2max substantially higher in athlete’s sport-specific

activity– 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