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听力原文：Olga: Hi Ben! Hi Sally! Come in.
Ben: Hi Olga!
Sally: Hi Olga!
Olga: Did you have any problems getting some basic information for our project on fitness assessments？
Ben: I didn't. There's plenty of information available nowadays, because so many people are interested in keeping fit.
Sally: Yes, I got some useful information we can use from websites
and Ben got some stuff from fitness centres in the city. Q21
Olga: Great! I found some things in magazines and newspapers. I Q22
think we might find the biggest problem is that we have too
much information. Anyway, let's begin. Now, a fitness assessment Q23
is a series of measurements that can help determine
physical fitness. There are several standard tests in a fitness
assessment. Depending upon the assessor, other tests may be
added to achieve a greater picture of fitness.
Sally: Or lack of it! According to my information, the main tests in
a fitness assessment evaluate body mass index, resting heart
rate and blood pressure, and aerobic fitness. Additional tests
may evaluate body composition, lung capacity, flexibility and
strength.
Ben: What exactly does the body mass index tell us about a person's fitness？
Sally: Body mass index evaluates a person in terms of their height and weight to determine total body mass. It can show if a person's body mass measurement exceeds normal limits and thus indicates that weight loss would be a good idea.
Ben: So, it's a bit inexact, then？
Olga: Yes, it is. BMI alone is usually not thought to be the best measure
of physical fitness. Someone who is very muscular may Q24
have a higher BMI than is considered normal, because muscle
weighs more. A true measurement of a body's fat content in a
fitness assessment may be better obtained through something
called hydrostatic weighing, which assesses the body's composition Q25
more exactly.
Ben: Hydrostatic weighing？ I've never heard of it.
Olga: I don't have any more information on it. We can make a note of it and look it up later. Sally, you said there were other ways of evaluating fitness？ Sally: Er ... yes. A typical fitness assessment. will also evaluate heart
rate and blood pressure. Measuring resting heart rate is important
because it allows you to figure out what the safe levels of increasing
the heart rate are during aerobic exercise. The basic
formula for measuring safe maximum heart rate is 220 minus Q26
age, minus resting heart rate. This figure is multiplied by 0.9 Q27
and the resting heart rate is added back to get the maximum
heart rate at which one can safely exercise. Olga: However, it says here that determining appropriate maximum
heart rate in a fitness assessment should also take into account
blood pressure. A person with high blood pressure should be Q28
evaluated by a physician prior to proceeding with an exercise
programme.
Ben: Definitely! Another common test in a fitness assessment is
aerobic fitness. This looks at the heart rate and oxygen rate Q29
during a moderate workout that may last five to ten minutes.
Evaluations about the ability of the blood to oxy
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