One of the limiting factors in human physical performance is the amount of oxygen that is absorbed by the muscles...
GMAT Critical Reasoning : (CR) Questions
One of the limiting factors in human physical performance is the amount of oxygen that is absorbed by the muscles from the bloodstream. Accordingly, entrepreneurs have begun selling at gymnasiums and health clubs bottles of drinking water, labeled "SuperOXY," that has extra oxygen dissolved in the water. Such water would be useless in improving physical performance, however, since the amount of oxygen in the blood of people who are exercising is already more than the muscle can absorb.
Which of the following, if true, would serve the same function in the argument as the statement in boldface?
Understanding the Passage
| Text from Passage | Analysis |
| "One of the limiting factors in human physical performance is the amount of oxygen that is absorbed by the muscles from the bloodstream." |
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| "Accordingly, entrepreneurs have begun selling at gymnasiums and health clubs bottles of drinking water, labeled 'SuperOXY,' that has extra oxygen dissolved in the water." |
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| "Such water would be useless in improving physical performance, however," |
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| (Boldface 1) "since the amount of oxygen in the blood of people who are exercising is already more than the muscle can absorb" |
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Overall Structure
The author presents a premise about oxygen limitation, describes an entrepreneurial response to that premise, then argues why that response is flawed. The flow moves from: general principle → business application → criticism of that application with supporting reasoning.
Main Conclusion: SuperOXY water would be useless in improving physical performance.
Boldface Segments
Boldface 1: the amount of oxygen in the blood of people who are exercising is already more than the muscle can absorb
Boldface Understanding
Boldface 1:
- Function: This serves as the key evidence/reasoning that supports the author's main conclusion that SuperOXY water is useless
- Direction: Supports the author's conclusion (same direction) - it explains why the author is right to dismiss the water as ineffective
Structural Classification
Boldface 1:
- Structural Role: Supporting evidence/premise for the main conclusion. It's the "because" statement that justifies why the water won't work
- Predicted Answer Patterns: Look for phrases like "provides evidence for," "supports the conclusion," "reason given for," "justifies the claim that"
This choice says 'world-class athletes turn in record performance without such water.' While this might suggest the water isn't necessary, it doesn't serve the same function as the boldface. The boldface explains a physiological mechanism for WHY the water won't work (excess oxygen already available), whereas this just shows that performance is possible without it. These serve different logical functions in supporting the conclusion.
This states 'frequent physical exercise increases the body's ability to take in and use oxygen.' This actually works against the argument rather than supporting it the same way as the boldface. If exercise increases oxygen absorption ability, this might suggest ways to improve the oxygen bottleneck, which doesn't align with the boldface's function of explaining why more blood oxygen won't help.
This says 'the only way to get oxygen into the bloodstream so that it can be absorbed by the muscles is through the lungs.' This serves the exact same function as the boldface - it provides a physiological reason why SuperOXY water won't work. If oxygen can only enter the bloodstream through the lungs, then drinking oxygen-enhanced water won't increase blood oxygen levels available to muscles. Both the boldface and this choice explain WHY the water is ineffective through biological mechanisms.
This states 'lack of oxygen is not the only factor limiting human physical performance.' This doesn't serve the same function as the boldface. The boldface specifically explains why adding more oxygen won't help (because there's already excess), while this choice broadens the discussion to other limiting factors. These address different aspects of the performance limitation issue.
This says 'the water lost in exercising can be replaced with ordinary tap water.' This focuses on hydration replacement rather than the oxygen enhancement aspect. It doesn't serve the same function as the boldface, which specifically addresses why extra oxygen in the blood won't improve performance. These statements support different aspects of why SuperOXY water might be unnecessary.