CASE TWO ANSWER/NOTES
What are the health benefits of exercise?
1. Reduced overall mortality – The best study, the Harvard alumni study shows that the relative risk for dying during the followup period (10-15 years) was 0.47 for most active compared with least active. Other huge studies show similar risk reductions (RRs of .47 to .7 for most active compared with least) . Further evidence for the association comes from good studies that show that people who were initially inactive and later became active have reduced mortality compared with ongoing sloths. In these studies the risk reduction from taking up exercise and becoming physically fit is of the same magnitude as quitting smoking.
2. Reduced Cardiovascular Mortality, CHD, and HTN – details in question 1 & 3.
3. Reduced risk of colon cancer – data insufficient to assess effect on other cancers or no association detected.
4. Reduced risk of Diabetes
5. Relieves symptoms of Depression and anxiety. May also reduce risk of developing depression.
How would you assess her current level of physical activity?
This is a bit of a problem. The studies documenting the above associations use many different methods for quantifying physical activity. While some assess only leisure-time activities, others include all daily activities. The problems in assessment are a bit akin to brief physician assessment of diet. Usually, it’s more revealing to ask people what they had for breakfast, lunch, dinner, and snacks, then it is to ask them what their diet consists of. Similarly, a daily recounting of occupational, housework, and leisure activities will give a ballpark idea of whether the patient is sedentary, minimally active, moderately active, or very active. (Anyone who goes to the gym three times a week is very active.) Also, keep in mind the general rules that every little bit helps and more is better (except at the extreme – marathoners and such). These general rules have solid data behind them. The aforementioned studies of all-cause mortality document graded relationships with moderate activities conveying some benefit. For example, walking 15 km per week reduced risk of dying during followup period to 0.67. That’s about 9 miles – if you walk half a mile to and from the subway station at both ends of the commute, you’re there. Another example, apropos of this and the previous question, is that men who climbed 55 flights of stairs per week had RR of death of 0.75.
Given her current situation, how might she go about getting more exercise?
Practical suggestions would be getting off the subway or bus one stop earlier and walking. Taking the stairs in her apartment building. Walking for short errands rather than riding the bus. Suggestions for leisure time activities should be conditioned by the very mixed results that “coercive” attempts at intervention have had and the knowledge that the measurable fitness benefits of exercise diminish significantly within 2 weeks of cessation and disappear completely within 8 months. If she’s going to take up something in her leisure time, it should be something she enjoys, that involves acceptable expense, that she can fit into her schedule, etc.
