EXSS1010 Lecture Notes - Lecture 5: Hemoglobin, Perfusion, Horse Length
30 May 2018
School
Department
Course
Professor
EXSS1010 - CARDIAC FUNCTION DURING EXERCISE
CARDIAC FUNCTION
1. Heart rate
2. Stroke volume
3. Cardiac output - how many litres our blood is pumping per minute
4. Blood pressure
HEART RATE
• Number of cardiac cycles per minute
o Measured as beats per minute (bpm)
• Controlled by both neural or endocrine mechanisms
• Resting Heart Rate (RHR)
o 60-p(↓5-30bpminenduranceathletes)
o ↓ ith age ad iproeets i aeroi fitess
o Changes with altitude and temperature
HEART RATE DURING EXERCISE
• Steady-state heart rate
o Plateau reached during constant rate of submaximal work
o A HR drift a e osered at high itesit or hot eiroets
• Maximum heart rate (HRmax)
o Linear increase with intensity until ~85%max
o APHRmax = 220 – age (but largely individual)
o Relatively consistent across time
STROKE VOLUME
• Volume of blood pumped per contraction (mL or L)
• SV = EDV – ESV
• End-diastolic volume (EDV) - volume of blood in ventricle before contraction
• End-systolic volume (ESV) - volume of blood in ventricle after contraction
• Ejection Fraction
o EF = SV/EDV
STROKE VOLUME IN EXERCISE
• Increases with work intensity up to 40% to 60% maximum
• May continue to increase up through maximal exercise intensity, generally in highly trained
athletes
• Greater refilling and stronger contraction of cardiac tissue
• ↑“V = ↑EDV – ↓E“V
CARDIAC OUTPUT
• Cardiac output (Q) expresses the amount of blood pumped by the heart each minute
• Reflects the functional capacity of the cardiovascular system
• Cardiac output (L/min)=Heart rate(bpm) x Stroke volume(L)
• Resting value for males ~5.0 L/min
• Q=70bmpx71mL=4970mL/minor4.97L/min
• Slightly lower in females ~4 L/min due to smaller stroke volume (SV)
CARDIAC OUTPUT AND EXERCISE
• Increases proportionately with exercise intensity
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Cardiac function: heart rate, stroke volume, cardiac output - how many litres our blood is pumping per minute, blood pressure. Heart rate: number of cardiac cycles per minute, measured as beats per minute (bpm, controlled by both neural or endocrine mechanisms, resting heart rate (rhr, 60-(cid:1012)(cid:1004)(cid:271)p(cid:373)( (cid:1006)5-30bpminenduranceathletes, (cid:449)ith age a(cid:374)d i(cid:373)pro(cid:448)e(cid:373)e(cid:374)ts i(cid:374) aero(cid:271)i(cid:272) fit(cid:374)ess. Increases with work intensity up to 40% to 60% maximum: may continue to increase up through maximal exercise intensity, generally in highly trained athletes, greater refilling and stronger contraction of cardiac tissue, v = edv e v. Cardiac output: cardiac output (q) expresses the amount of blood pumped by the heart each minute, reflects the functional capacity of the cardiovascular system, cardiac output (l/min)=heart rate(bpm) x stroke volume(l, resting value for males ~5. 0 l/min, q=70bmpx71ml=4970ml/minor4. 97l/min. Slightly lower in females ~4 l/min due to smaller stroke volume (sv)
