Medical researcher: Scientists compared a large group of joggers who habitually stretch before jogging to an equal nu...

shunhe on September 29, 2020

Hi @CMarr,

Thanks for the question! Let’s take a look at the stimulus here. We’re told that scientists compared joggers who habitually stretch before jogging to an equal number of joggers who don’t. And turns out, both groups have about the same number of injuries. So, the argument concludes, stretching before jogging doesn’t help to prevent injuries.

We’re asked for something that would most weaken the medical researcher’s argument. (E) tells us that studies have found that, for certain forms of exercise, stretching beforehand can reduce the severity of injuries resulting from that exercise. Does this weaken the argument? No, it doesn’t. Take a careful look at what the argument is about. It’s about the number of injuries, not the severity of injuries. (E) talks about the severity of injuries, which is a different concept and thus irrelevant for this argument.

Now take a look at (D), which tells us the more prone a jogger is to jogging injuries, the more likely he or she is to develop the habit of performing stretches before jogging. So basically, joggers who are more likely to get injured are more likely to stretch. Which probably means that since the two groups have the same number of injuries and are the same size, the stretching did help, because otherwise we’d expect the stretching group to have more injuries! And if the stretching helps lower the number of injuries, then that weakens the conclusion, which

Hope this helps! Feel free to ask any other questions that you might have.