Codes and Frequencies
For sample adults who do moderate physical activities (VIG10FTP), VIG10DTP reports the time period (minutes or hours) during which they engaged in vigorous leisure-time physical activities. Prior to 2020, the survey text inquired specifically about exercise that lasted at least 10 minutes. This variable must be interpreted in conjunction with the variable VIG10DNO, which reports the duration in number of units corresponding to the time period reported in VIG10DTP. For example, a respondent who jogs for 30 minutes would have a VIG10DNO value of 30 and a VIG10DTP value of 1 (which is the IPUMS NHIS code for "minutes").
VIG10DMIN, a recoded variable created by the staff at the National Center for Health Statistics, draws upon the information in VIG10DNO and VIG10DTP and reports the duration of vigorous physical activity in a standardized unit of time, minutes.
Leisure-time vigorous activities are described in the survey questionnaire as activities that "cause heavy sweating or large increases in breathing or heart rate." The Field Representative's Manual provides examples of vigorous 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.
Beginning in 2020, individuals with a duration value (ascertained through combining VIG10DNO and VOG10DTP) equivalent to 720 minutes or 12 hours or more were coded as "3 - Extreme value." Additionally, the 2020 Survey Description notes that "an instrument error in 2020 allowed for entries of more than 24 hours in duration" (85). These entries were recoded to "Extreme value."
For further discussion of data collection on leisure-time physical activity in general for 1997 forward, see VIG10FNO (Frequency of vigorous activity 10+ minutes: Number of units).
VIG10DTP is available beginning in quarter 3 of 1997. For data on the duration of respondents' vigorous activity in the first half of 1997, see VIG20DTP2.
The question wording for VIG10DTP changed slightly in 2004.
For all years from 1997 forward, the survey section on physical activity began with the statement, "The next questions are about physical activities (exercise, sports, physically active hobbies ...) that you may do in your leisure time." Beginning in 2004, the question about duration of vigorous activities reiterated the point that respondents were only to report leisure-time activities. From 1997 through 2003, interviewers asked, "About how long do you do these vigorous activities each time"; for 2004 forward, they asked, "About how long do you do these vigorous leisure-time physical activities each time?" Thus, beginning in 2004, the question wording made explicit what had previously been implicit and had been specified in the introductory statement only.
Prior to 2020, the series of questions about vigorous physical activity included that the exercise last at least 10 minutes. Beginning in 2020, people who report engaging in vigorous physical exercise in VIG10FTP are in universe for VIG10DNO, regardless of whether they typically engaged in such exercise for at least 10 minutes.
Additionally, while the basic meaning of this variable is completely comparable over time, major questionnaire changes introduced in 2019 may affect comparability with earlier years. The NHIS questionnaire was substantially redesigned in 2019 to introduce a different data collection structure and new content. For more information on changes in terminology, universes, and data collection methods beginning in 2019, please see the user note.
- 1997: Sample adults age 18+ in quarters 3 and 4 who participate in vigorous activities for at least 10 minutes.
- 1998-2018: Sample adults age 18+ who participate in vigorous activities for at least 10 minutes.
- 2020: Sample adults age 18+ who do vigorous physical activities (VIG10FTP
- 1997-2018, 2020
- 1997-2018, 2020 : SAMPWEIGHT