Narrator: Now listen to part of a lecture on the topic you just read about.
Professor: Okay, HIIT. High-intensity training. It sounds too good to be true, right? It’s not necessarily that it doesn’t work. But, think about the practical issues. All of the studies on HIIT, they make it clear that it’s not just going for a hard run or doing a hard interval on the bike. In order for the effect on your metabolism to show up, you have to be working way harder than you’d think—you have to really be putting out maximum effort. If you do it correctly, HIIT will often make you feel sick and it’s pretty painful. If you try to use HIIT to get people into exercise, you’ll get some people who try it, feel terrible, and give up. Or, you’ll get people who don’t do it hard enough.
Plus, there’s the problem of injury. Most people, their joints, ligaments, even their bones, they’re not really ready for a maximum-intensity effort. It’s more of a technique for people who are already in good shape, because they can go hard without hurting themselves. But how did they get in good shape to begin with? They did it by doing longer, easier workouts.
There’s also the issue of the studies on HIIT. Especially back when HIIT first came about—in the 1990s—it was hard to measure changes in body fat. You’d have to use calipers to measure the fat at various points on a person’s body. But studies have shown that people who try to measure with calipers, even people who are really experienced, have a very high rate of error. So if a study shows a small difference in fat loss, if they used calipers, you probably shouldn’t trust it. And that’s the case with most HIIT studies so far.
The lecturer disagrees with the passage that HIIT is a beneficial workout that can increase public level of exercise or fitness. The passage states that HIIT is effective because it is a high-intnsity workout that has ongoing benefits after the workout is completed. The workout only takes a few minutes to do, contrasting between high intensity exercise and then rest periods, but people continue to burn fat for hours after the workout. This phenomenon is called EPOC, which helps you lose fat even when you’re not active.
While the passage says that HIIT helps people to lose more fat, the lecturer thinks that HIIT is impractical for the general public. Most people just aren’t capable for that amount of intensity. Or if they are, they might get sick, feel pain, or even injured, which would deter them from wanting to continue. The lecturer thinks this would only be a beneficial exercise regimen for very fit people, but to get very fit, you’d have to do standard exrcise in the first place.
The lecturer also brings up the use of calipers to measure fat loss in the HIIT studies. According to the lecturer, calipers have been proven to be unreliable for measuring fat, and calipers were used in most of the HIIT studies that have occured this far. As a result, it may be the case that the HIIT studies are unreliable. People may not have lost as much fat as the studies claimed.
The student summarizes the passage and then explains how the lecturer refutes the points made in the passage. Note that the question asks only about the second part: how the lecturer challenges the passage. The student spent most of the first paragraph summarizing the passage. He still earned a good score because he wrote about the lecturer’s opinion in the second and third paragraphs, but if he had run out of time, he might not have earned such a good score.