Question

The Harvard Alumni Study measured physical activity at two times points, approximately 11-15 years apart. Which of the following describes individuals who did not expend >2000 Kcals/week at the first time point, but had increased their physical activity to this level at the second time point?

a.) Their relative risk of dying prematurely was equal to those who did not expend >2000 Kcal/week at either time point.
b.) Their relative risk of dying prematurely decreased slightly, but not enough to recommend that inactive individuals become active later in life.
c.) Their relative risk of dying prematurely was comparable to those who expended >2000 Kcals/week at the first time point, but not at the second time point.
d.) Their relative risk of dying prematurely decreased substantially, approaching the level of individuals who expended >2000 Kcals/week at both time points.

Answer 1

The Harvard Alumni Study found that individuals who increased their physical activity to expend more than 2000 Kcals/week by the second measurement point significantly reduced their relative risk of dying prematurely, approaching those who were consistently active at both time points.

Step-by-step explanation:

The Harvard Alumni Study investigated changes in physical activity levels and their association with mortality risk. The question pertains to individuals who were not expending more than 2000 Kcals per week at the first measurement point, but increased their activity to exceed this threshold by the second measurement point. According to the information provided, these individuals likely saw a decrease in their relative risk of dying prematurely. This is consistent with the broader literature that suggests that increasing physical activity levels to meet or exceed health guidelines can lead to substantial health benefits, including a reduced risk of chronic diseases and mortality.

Furthermore, based on the recommendations from the U.S. Department of Health and Human Services and the evidence of added years to life expectancy through regular physical activity, it can be inferred that those who increase their activity to a significant degree, such as expending more than 2000 Kcals per week, would have a decreased risk of premature death. Therefore, the correct answer is that their relative risk of dying prematurely decreased substantially, approaching the level of individuals who expended >2000 Kcals/week at both time points.