PrepTest 119, Section 2, Question 12
Researcher: We studied two groups of subjects over(75 more words not shown)
The researcher's statements, if true,(8 more words not shown)
- ARegular afternoon exercise(9 more words not shown)
- BExercise in the(19 more words not shown)
- CThe best way(16 more words not shown)
- DNo one in(12 more words not shown)
- ERaising body temperature(15 more words not shown)
Reading the argument
Maybe exercise isn't the only way to get that extra heat.
The exercise group got 33 percent more deep sleep than the group doing little or no exercise. Looking at a study like this, I'd normally want to know what else differed between the groups. Did they eat differently, for example? The sleep difference alone wouldn't identify exercise as the cause.
But the researcher gives us more than the group comparison. The final sentence says afternoon exercise slightly raises body temperature until after bedtime, and that extra heat induces deeper sleep. For this question, we're asked to accept those statements and identify what they most strongly support. We shouldn't spend the answer choices disputing the mechanism we've been given.
What we’re looking for
If the extra heat is doing the work, perhaps another way of slightly raising body temperature could have a similar effect. A sauna comes to mind as a possibility. I don't need that particular method in the answer; I'm looking for the same modest temperature increase and its stated effect on sleep.
Working the answers
- A
Helpful doesn't mean required. Exercise supplies one route to the temperature increase, but the researcher doesn't say it is the only route to adequate deep sleep. People might sleep adequately without exercising in the afternoon. A turns a benefit into a requirement.
- B
We have no comparison with morning exercise. Perhaps its effect on body temperature doesn't last until bedtime, or perhaps it offers other benefits. The passage doesn't establish that morning and afternoon exercise are nearly equal in their effects on sleep.
- C
We haven't ranked all methods of increasing deep sleep. A slight temperature increase might help while some other approach helps more. Also, the study describes exercise raising temperature until after bedtime, not a comparison proving that beginning the increase just before bed is best.
- D
Doing little or no exercise doesn't mean a person's temperature never rises. Someone in the control group could become warmer for another reason. The group difference in deep sleep doesn't establish that no individual in the control group experienced this temperature change.
- ECorrect
This uses the mechanism the researcher supplies: a slight increase in body temperature promotes deeper sleep. The answer changes the source of that increase from exercise to a warm bath just before bed. If the bath produces the relevant warming, the stated mechanism gives us reason to expect increased deep sleep.
The answer says “likely,” which fits the support we're given. We don't need to promise an identical result for every person or the exact 33 percent difference seen between the study groups.
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