Codes and Frequencies
VIG20FTP reports the time period (never, day, week, month, year) that respondents used to describe the frequency of vigorous physical activity that they engaged in for at least 20 minutes. This variable must be interpreted in conjunction with VIG20FNO, which reports the number of units corresponding to the time period in VIG20FTP. For example, a respondent who runs once a day would have a VIG20FNO value of 1 (to indicate 1 time) and a VIG20FTP value of 2 (which is the IPUMS NHIS code for "day").
VIG20FWK, a recoded variable created by the staff at the National Center for Health Statistics, draws upon the information in VIG20FTP and VIG20FNO and reports the frequency of vigorous leisure-time physical activities in terms of a single time unit, times per week.
Vigorous activities are described in the survey question itself as activities that "cause heavy sweating or large increases in breathing or heart rate." The Field Representative's Manuals for 1997 forward provide examples of vigorous leisure-time physical activities, although these examples were not routinely shared with respondents. These examples include fast walking, fast bicycling, jogging, strenuous swimming or sports play, vigorous aerobic dance, and strenuous gardening.
VIG20FTP is only available for 1997 and is provided to allow comparability across all quarters of that year.
During the first half of 1997, due to an error of the wording of the survey question, respondents were asked how frequently they engaged in physical activities lasting a minimum of 20 minutes. This mistake was corrected beginning in quarter 3 of 1997, when the minimum duration of physical activity was lowered to 10 minutes.
To allow analysis of vigorous leisure-time physical activity across all quarters of 1997, the National Center for Health Statistics created "transitional" variables (such as VIG20FTP) that cover all quarters of 1997.
These transitional variables combined the data on vigorous leisure-time physical activity for at least 20 minutes from quarters 1 and 2, with data from the subset of respondents in quarters 3 and 4 who engaged in vigorous leisure-time physical activity for at least 20 minutes. In other words, the transitional variables for 1997 allow comparability across all quarters of 1997 only by excluding respondents from quarters 3 and 4 whose physical activity lasted between 10 and 19 minutes (i.e., less than 20 minutes in duration). Researchers who wish to analyze data on vigorous physical activity (for 20+ minutes) for all quarters of 1997 can use these transitional variables. For the full list of these transitional variables, which cover 1997 only and are restricted to adults who exercised vigorously for at least 20 minutes, see VIG20FNO.
Researchers who wish to analyze data from multiple years on adults' leisure-time vigorous physical activity should restrict their data from 1997 to quarters 3 and 4 and use variables beginning with "VIG10."
See VIG10FNO for an overview of the variables relating to adults' leisure-time physical activity for at least 10 minutes for the third quarter of 1997 forward.
- 1997: Sample adults age 18+. (For quarters 3 and 4, persons who reported a duration of 10-19 minutes of vigorous activity are excluded.)
- 1997 : SAMPWEIGHT