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

PyjamaScientist read the condition i mentioned then let me know whether it matters or not.

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.

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.

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.

DmitryFarber
hey, could you please provide an explanation for (B),

the assumption here is that both A and B will respond similarly with respect to their VO2 max to how they responded previously (when they were doing moderate aerobic exercise)

is (B) a paraphrase of this assumption?

Well, they don't have to respond similarly in the sense that their VO2 max stays the same. We just need to see that if they improve, they improve by a similar amount so that A stays ahead.

The premise is that they had the same VO2 max after engaging in moderate activity. The author then predicts that once they start intensive training, A will stay ahead of B on this measurement. This overlooks the possibility that B might somehow improve, even if they do the same level of training and neither becomes injured. Perhaps B will make other helpful lifestyle changes (e.g. diet, medication, etc.), or A will make unhelpful changes, or even if neither makes any changes, maybe B will just get more benefit from the training. That last bit is what answer choice B is saying. The author is assuming that B won't respond better, and that instead they will both have the same benefit from the training.