During the period in which there are no competitive races, two runners

What we know:
a) Experiment is being conducted to measure the VO2 Max(volume of oxygen an athlete can use).
b) 1st experiment moderate aerobic exercise (heart rate b/w 146-154) Runner A had greater VO2 max than Runner B had.
c) 2nd experiment intensive exercise (heart rate>168) has to be conducted.

A conclusion has been drawn from the result of experiment one that Runner A will have greater VO2 max here also than VO2 max of Runner B

What assumption has been taken into account in drawing the conclusion:
Pre-thinking says it has been assumed that both trainers will respond equally to the intensive training, hence the consumption of oxygen will increase at the same rate because if exercise 2 put more strain on runner A than on B than runner A's VO2 max will reduce.

(A) Runner A and Runner B had similar VO2 maxes upon entering the study.
Negating the statement : They had dissimilar VO2 max upon entering the study it doesn't breaks the conclusion as even though they had different VO2 max the benchmark was set after the first experiment.(so the difference is already accounted for also the difference will remain the same for the second experiment as well) here the comparison is between the results of two experiments.

(B) Regarding their VO2 maxes, runners respond equally to intensive training.
In line with our pre-thinking:
Negating the statement: Runners response to intensive training was different
condition 1: It put more strain on runner A hence he consumed more oxygen, the strain was similar to the aerobic exercise for runner B hence he consumed same amount of oxygen.
In this case the conclusion breaks. Hence our answer.

(C) Intensive training involves sessions in which athletes maintain a heartbeat over 168 beats per minute.
Already stated and irrelevant.

(D) The amount one trains does not influence one’s VO2 max.
They trained with similar intensity and if it has no effect on VO2 max. Irrelevant.

(E) During the experiment, Runner A did not always have the greater VO2 max than Runner B.
We are concerned about the result not what happened during the process.
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In my opinion, Answer B is incorrect, because it says "runners respond equally to intensive training". If something is an assumption, it needs to be true for the argument to hold. And we don't need to assume they respond equally to intensive training for the argument to be true. The argument is still true if high-VO2 runners in moderate training respond better than low-VO2 runners to intensive training.
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PyjamaScientist read the condition i mentioned then let me know whether it matters or not.
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If they responded equally, then they would have same VOX2 level. Right?

thakurarun85

Think this way there are two rubber bands A and B
In the first experiment stress of 100 joules was applied :
It expanded the rubber band A by 20 cm and B by 40 cm.
So the rate of expansion for A is 1/5cm/joule and B is 2/5cm/joule. (With me so far.?)

Now the force of stress has been increased to 200Joules.
Now the question to be asked here is, to get the same result as the first experiment I need the rubber bands to react the same way as they did in the first experiment. Yes or No.? (This is what option B is saying, they responded equally i.e rubber bands expanded at the same rate as in the first stress)
Because if when 200 joules was applied if rubber band A expanded to 80 instead of 40 and B maintained its rate and expanded to 80.
Then we can't say rubber band had more room to expand than rubber band B.

I tried my best to break the stuff down in best possible way I can. Hope the doubt got cleared.
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I really appreciate your response. Thanks for that.

So B actually saying that the runners response will be equal to what they respond in medium intensity training.

Now the rubber example you gave will give different results if there is differential strain level (~VOX max) already present. So I think in such case A is also correct assumption. What do you say?

thakurarun85 No.! How come.?

Option A is saying they had similar VO2 max upon entering. If I compare this with the rubber band example it simply signifies both bands have equal room for expansion. i.e if A can expand from 0 to 100 cm then B can also expand 100 cm. Which need not be true.
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OFFICIAL EXPLANATION

Premise #1 – A > B (VO2 max) after moderate aerobic activity.

Conclusion: Runners will begin identical intensive training, A will continue to have greater V02 max.

Assumption: The effects of intensive training on the two runners are equivalent to the effects of moderate aerobic training.

(A) directly contradicts what is stated in the passage: Runner A had a greater VO2 max than B.

(B), if it is not true, represents a possible flaw in the conclusion. Say Runner A responds to intensive training differently than Runner B, then it is possible that Runner A will NOT have a greater VO2 max than runner B.

(C) just quantifies what is meant by intensive training. It doesn’t relate to the argument as a whole.

(D) is tempting but remember the argument says that “both will train with similar intensity” and will engage in “identical intensive training”.

(E) is somewhat of a weakener. That is, it points to the possibility that the VO2 max fluctuated throughout the experiment and Runner A just happened to have the higher VO2 max at the very end of training.

An assumption, however, doesn’t weaken the conclusion, but is the very foundation upon which the conclusion rests. That’s why we negate assumptions. In other words, if I pull the foundation out from under the house and that house still stands, then the original assumption was not one that supported the conclusion. However, if I negate the assumption and the conclusion then totally falls apart, we know the original assumption is one upon which the argument depends.

By negating (E), “Runner A always had the greater VO2 max…”, we actually strengthen the conclusion. Therefore, (E) is not the answer.
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