Exercise physiology: responses and recovery
הוצג| English | משמעות |
|---|---|
| cardiac output/ˈkɑːdiæk ˈaʊtpʊt/ | נפח דם לבבי |
| stroke volume/strəʊk ˈvɒljuːm/ | נפח פעימה |
What would explain this observation?
- Heart rate increases during a short exercise bout, then recovers. This time course connects energy demand, oxygen transport and cardiovascular regulation.
Build the model
- Cardiac output 心输出量 is heart rate multiplied by stroke volume 每搏输出量.
- Ventilation supports gas exchange, while blood transport delivers oxygen to working tissues.
- ATP demand changes as muscle activity changes.
- cardiac output: Blood volume pumped per minute.
- stroke volume: Blood volume pumped per beat.
Which distinguishes a training adaptation from an acute response?
רמת קושי 1/5 · 100 מטבעות + בונוס קטן בהשלמה הראשונה היום
An adaptation is a lasting change built over repeated training sessions, such as increased stroke volume. An acute response, like a raised heart rate during one session, appears and fades immediately; the time course is what distinguishes them.
Match each technical term to its precise meaning.
רמת קושי 2/5 · 140 מטבעות + בונוס קטן בהשלמה הראשונה היום
Use the definitions to distinguish related quantities and processes.
Choose evidence that can test it
- An acute response occurs during or soon after exercise.
- A training adaptation develops over repeated sessions.
- A lower post-exercise heart rate cannot alone establish greater fitness without comparable workload and participant conditions.
In the lab: Use voluntary informed participation, school supervision and an approved low-intensity protocol. Record baseline, a standardized workload and timed recovery measurements. Stop for discomfort and do not use maximal exertion or health diagnosis as a classroom task.
Which two habits make the investigation or model in this case more defensible?
רמת קושי 2/5 · 140 מטבעות + בונוס קטן בהשלמה הראשונה היום
Stating the conditions and assumptions lets others repeat the work exactly, and recording the supporting evidence lets them check the conclusion. Hiding disagreeing results removes the evidence that could challenge a wrong conclusion, and one measurement can never establish a wider claim.
Work from known quantities
- Known: heart rate is 120 beats per minute and stroke volume 80 millilitres per beat.
- Cardiac output = heart rate × stroke volume = 120×80 = 9,600 millilitres per minute = 9.6 litres per minute.
Your turn: Heart rate is 100 beats/min and stroke volume is 70 mL/beat. Find cardiac output in L/min.
Heart rate is 100 beats/min and stroke volume is 70 mL/beat. Find cardiac output in L/min.
רמת קושי 2/5 · 140 מטבעות + בונוס קטן בהשלמה הראשונה היום
The result is 7 L/min. Known: heart rate 100 beats per minute; stroke volume 70 mL per beat. Use cardiac output = heart rate x stroke volume. Cardiac output = 100 x 70 = 7,000 mL per minute = 7 litres per minute.
Check the conclusion and its limits
- A heart-rate monitor measures one response, not every dimension of performance.
- Hydration, stress, medication and recent activity can confound comparisons.
Not true: A single heart-rate reading proves a person fitness level. One heart-rate reading mixes fitness with hydration, stress, caffeine, posture and recent activity. Fitness judgements need repeated measurements under controlled conditions, and heart rate alone says nothing about strength or skill.
- Cardiac output is heart rate multiplied by stroke volume.
- An acute response occurs during or soon after exercise.
- Watch for: A heart-rate monitor measures one response, not every dimension of performance.
Write from a cardiac output of 5.4 litres per minute
- Heart rate is 90 beats per minute and stroke volume is 60 millilitres per beat.
- Find the cardiac output. One heart-rate reading does not prove fitness.
One heart-rate reading mixes fitness with hydration, stress, caffeine, posture and recent activity.
רמת קושי 1/5 · 100 מטבעות + בונוס קטן בהשלמה הראשונה היום
True. One heart-rate reading mixes fitness with hydration, stress, caffeine, posture and recent activity. Fitness judgements need repeated measurements under controlled conditions, and heart rate alone says nothing about strength or skill.
Blood volume pumped per minute: write the technical term.
רמת קושי 1/5 · 100 מטבעות + בונוס קטן בהשלמה הראשונה היום
cardiac output means Blood volume pumped per minute.
Heart rate is 90 beats per minute and stroke volume is 60 millilitres per beat. What is the cardiac output, and why does one heart-rate reading not prove fitness?
Cardiac output is heart rate times stroke volume. A single reading is not a fitness test.
What is the cardiac output?
רמת קושי 1/5 · 100 מטבעות + בונוס קטן בהשלמה הראשונה היום
90 times 60 millilitres is 5,400 millilitres per minute, which is 5.4 litres per minute. Other options — 90 litres per minute (the heart rate); 60 litres per minute (the stroke volume).