ACUTE R

ESPONSES T

O EXERCIS

E

ACUTE RESPONSES TO EXERCISE

Acute Responses to Exercise are the immediatephysiological responses to exercise.

ACUTE RESPONSES TO EXERCISE

Cardiovascular ResponsesHeart Rate (HR) – measured in beats per minute bpm

• Increase – sub max (steady state)

• Increase linearly until predicted max

• Predicted maximum is a calculation – 220-Age = no change

ACUTE RESPONSES TO EXERCISE

Cardiovascular ResponsesStroke Volume (SV) – Volume of Bloodthe volume of blood pumped from the Left ventricle of the heart with each beat.

• Increases as heart contracts more forcefully

• Rest = 60 – 80 mL per beat• Max Stroke Volume = 90 -120 mL per beat reached during sub max exercise

ACUTE RESPONSES TO EXERCISE

Cardiovascular ResponsesCardiac Output (Q)

From Wikipedia, the free encyclopedia

Cardiac output (Q) is the volume of blood being pumped by the heart, in particular by a ventricle in a minute. An average cardiac output would be 5L.min-1 for a human male and 4.5L.min-1 for a female

Q = SV x HR

ACUTE RESPONSES TO EXERCISE

Cardiac Output (Q)

• Rest = 4-6 litres of blood pumped per

minute.

• Cardiac Output increases to steady state at

constant pace or linearly with increasing intensity up to

exhaustion

 

 

ACUTE RESPONSES TO EXERCISE

Cardiovascular ResponsesBlood Pressure is the pressure exerted against the arterial wall

Systole and Diastole

Systolic Pressure Increases as greater volume of blood fills the

arteries

Diastolic Pressure remains fairly constant

ACUTE RESPONSES TO EXERCISE

Blood Flow

80 – 85% Q to working muscles

• Decrease in blood flow to the organs

• Increase to lungs

• Increase coronary blood flow

ACUTE RESPONSES TO EXERCISE

Cardiovascular ResponsesArterio-Venous Oxygen Difference (A-VO2) is the difference in the Oxygen Concentration between the arteries and the veins

• Increase from rest (more blood absorbed into muscles)

• a-vO2 diff at rest = 6mL/100mL  

• a-vO2 = 19mL/100mL (artery) – 4mL/100mL (vein) = 15mL/100mL

ACUTE RESPONSES TO EXERCISE

Cardiovascular ResponsesBlood Plasma is the yellow liquid component of blood inwhich the blood cells in whole blood are normally suspended.

It makes up about 55% of the total blood volume. It is theintravascular fluid part of extracellular fluid (all body fluid outside of

cells).

It is mostly water (93% by volume) and contains dissolved proteins, glucose,

clotting factors, mineral ions, hormones and carbon dioxide (plasma being

the main medium for excretory product transportation).

Decreases due to increased sweating

ACUTE RESPONSES TO EXERCISE

Respiratory ResponsesRespiratory Rate (breaths/min)

• 12 -15 breaths per minute at rest

• 40 - 50 breaths per minute during exercise

ACUTE RESPONSES TO EXERCISE

Respiratory ResponsesTidal volume is the lung volume representing the normalvolume of air displaced between normal inhalation andexhalation when extra effort is not applied. Increased

 

ACUTE RESPONSES TO EXERCISE

Respiratory ResponsesVentilation = Respiratory Rate x Tidal Volume

At restV = 0.5 litres x 12 breaths per min V = 6 litres/min During ExerciseV = 2.5 litres x 45 breaths per minV = 112.5 litres

ACUTE RESPONSES TO EXERCISE

Respiratory ResponsesLung DiffusionIncreases due to increase in Blood Flow and dilation of

capillaries surrounding the alveoli

 Oxygen Uptake (VO2)Increases as body absorbs more oxygen and uses it to

produce more aerobic energy

ACUTE RESPONSES TO EXERCISE

Muscular Adaptations

ACUTE RESPONSES TO EXERCISE

Muscular Adaptations• Increased number of muscular contractions

• Increased motor unit activation

• Increased muscle temperature

CHRONIC RESPONSES TO EXERCISE

Muscular Adaptations• Depletion of ATP/PC stores

• Depletion of Glycogen and Triglyceride stores

 

ACUTE RESPONSES TO EXERCISE

Muscular Adaptations• Increased blood flow as capillaries dilate

• Increased oxygen extraction

• Increased enzyme activity