Melicia C. Whitt

Compendium of physical activities: an update of activity codes and MET intensities.

We provide an updated version of the Compendium of Physical Activities, a coding scheme that classifies specific physical activity (PA) by rate of energy expenditure. It was developed to enhance the comparability of results across studies using self-reports of PA. The Compendium coding scheme links a five-digit code that describes physical activities by major headings (e.g., occupation, transportation, etc.) and specific activities within each major heading with its intensity, defined as the ratio of work metabolic rate to a standard resting metabolic rate (MET). Energy expenditure in MET-minutes, MET-hours, kcal, or kcal per kilogram body weight can be estimated for specific activities by type or MET intensity. Additions to the Compendium were obtained from studies describing daily PA patterns of adults and studies measuring the energy cost of specific physical activities in field settings. The updated version includes two new major headings of volunteer and religious activities, extends the number of specific activities from 477 to 605, and provides updated MET intensity levels for selected activities.

Moderate physical activity patterns of minority women: the Cross-Cultural Activity Participation Study.

Using data from 12 days of detailed physical activity records (PA records), we analyzed the physical activity patterns of 141 African American and Native American women, ages 40 and older, enrolled in the Cross-Cultural Activity Participation Study. PA records were completed every other month for three consecutive 4-day periods. The proportion of women who met the 1993 Centers for Disease Control and Prevention and the American College of Sports Medicine recommendation to accumulate at least 30 minutes of moderate intensity activity during most days of the week (at least 3 days of the 4-day periods) ranged from 63% to 70%. Nearly one third of women met the recommendation for more than one 4-day period. On days when subjects accumulated at least 30 minutes of moderate activity, time spent in moderate activity was 112 minutes/day. Most women performed household chores (95%, median = 24 minutes/day), walking for exercise (87%, median = 30 minutes/day), occupational (65%, median = 37 minutes/day), child care (53%, median = 32 minutes/day), and lawn and garden activities (51%, median = 43 minutes/day). Fewer than 25% reported conditioning and sports activities. In general, more Native Americans than African Americans were active in moderate activities. In conclusion, definitions used to characterize regular physical activity should be consistent among studies, and physical activity surveys among women should include occupation-related and home-related activities.

The relationship between pedometer-determined ambulatory activity and body composition variables.

OBJECTIVE: To examine the relationship between pedometer-determined ambulatory activity (steps/day) and body composition variables body mass index (BMI) and percentage body fat).DESIGN: Secondary analysis of a cross-sectional objective activity monitoring study for up to 21 consecutive days.SUBJECTS: A total of 109 apparently healthy adults (eight African American males, 23 African-American females, 33 Caucasian males, 45 Caucasian females), age 44.9±15.8 y, BMI=26.9±5.1 kg/m2.MEASUREMENTS: Pedometer-assessed ambulatory activity (steps/day), height and weight, and percentage body fat by bioelectrical impedance.RESULTS: Analyzed as both a continuous and a categorical variable (determined using 25th and 75th percentiles for distribution for steps/day), ambulatory activity was consistently related to body composition variables. Steps/day was inversely correlated with BMI and percentage body fat (r=−0.30, and r=−0.27, respectively, both P<0.01). The consistency of the relationship was also evident when examined using accepted BMI cut-off points for normal-weight, overweight, and obese categories.CONCLUSIONS: Individuals in this small sample with values greater than approximately 9000 steps/day are more frequently classified as normal weight for height. Individuals with values less than approximately 5000 steps/day are more frequently classified as obese. These findings require further corroborative investigation but provide preliminary cutoff points for identifying individuals at risk who may benefit from appropriate physical activity intervention.

Walking Patterns in a Sample of African American, Native American, and Caucasian Women: The Cross-Cultural Activity Participation Study:

This analysis describes walking patterns among African American, Native American, and Caucasian women from South Carolina and New Mexico. Walking was assessed using pedometer and physical activity (PA) record data based on 4 consecutive days on either three (Study Phase 1) or two (Study Phase 2) occasions. Participants walked 5,429 ± 2,959 steps per day and recorded 159 ± 59 minutes per day of total walking in the PA record. Most daily walking was accumulated during household (46%), transportation (26%), occupation (16%), and exercise-related (10%) walking. There was a modest correlation between steps per day and minutes per day. Steps per day were higher with education and household size, and lower with increasing age and body mass index. These findings have implications for developing PA surveys and for planning interventions related to walking patterns among women.

Amount and bouts of physical activity in a sample of African-American women.

PURPOSE To describe physical activity (PA) patterns in a sample of African-American women in comparison with the national recommendation for moderate PA. METHODS Volunteers (N=55; ages 25-55 yr (mean +/- SD 39.6 +/- 8.7); body mass index [BMI] 17.9-56.4 kg.m(-2) (31.3 +/- 7.9 kg.m(-2))) were recruited by word of mouth. PA was measured using accelerometers, pedometers, and PA records for two 4-d periods. RESULTS Participants accumulated 31.9 +/- 18.0 min.d(-1) in moderate-to-vigorous PA (MVPA), primarily through short bouts lasting 1-4 (median 11.9 bouts.d(-1)) and 5-7 min (median 0.6 bouts.d(-1)) but only on 3.1 +/- 2.4 d.wk(-1). Women with BMI<25.0 kg.m(-2) accumulated more daily PA than those with BMI 25.0-29.9 kg.m(-2) or > or =30 kg.m(-2) (50.3, 32.0, and 25.3 min.d(-1), respectively; P<0.001) and on more days per week (5.8, 3.0, 2.3 d, respectively; P<0.001). Of 42 women who completed both PA data collection periods, 17 achieved > or =30 min of MVPA on > or =5 of 8 d; however, only two achieved the PA in the recommended pattern (one 30-min bout or several 8-10 min bouts). CONCLUSION The current study showed that, although this sample was not sedentary, few participants met the activity level recommended for health benefits because activity was performed on too few days per week, particularly among overweight and obese participants. In addition, the bout pattern for most participants was not at the recommended length of at least 8-10 min. This suggests that additional emphasis on the recommended days per week and bout length may be necessary when counseling individuals about physical activity.

Agreement between participant-rated and compendium-coded intensity of daily activities in a triethnic sample of women ages 40 years and older.

Participant-rated and compendium-coded intensity of daily physical activities were compared in 148 African American, 144 Native American, 51 non-Hispanic White women ages 40 to 91 years who completed 4 days of activity records. For compendium-coded intensity, reported activities were classified as light (> 3 metabolic equivalents [METS]), moderate (3–6 METS), or vigorous (< 6 METS) using the Compendium of Physical Activities (1), whereas these categories were self-assigned for participant-rated intensity. Minutes per day (min/d) spent in activities at each intensity level were computed. Relative to compendium-coded min/d, participants reported significantly greater time spent in light (+10 min/d; p > .01) and vigorous (+17 min/d; p > .001) activities, and less time spent in moderate activities (−27 min/d; p > .001). Similarly, compendium-coded estimates yielded higher rates of participants meeting Centers for Disease Control and Prevention-American College of Sports Medicine and Surgeon General recommendations than participant-rated estimates (11–18% differences) but substantially lower rates meeting American College of Sports Medicine vigorous recommendations (22% difference). Further, 247 greater kilocalories per day were estimated based on compendium-coded intensity. Kilocalories per day estimates based on compendium codings were more highly associated with pedometer counts than those based on participant ratings (p > .05). Study patterns were generally seen across all sample subgroups. Discrepancies between participant and compendium estimates are likely to be most meaningful in studies estimating energy expenditure as it relates to health outcomes and in studies estimating vigorous activities.

Observations from the CDC: Evaluation of a Two-Part Survey Item to Assess Moderate Physical Activity: The Cross-Cultural Activity Participation Study

PURPOSE This study evaluated a two-part survey item that assessed adherence to the national moderate physical activity (MPA) recommendation (>/=30 min/day on >/=5 days/week). METHODS Participants were African American (n = 137), Native American (n = 129), and Caucasian (n = 50) women >/= 40 years from South Carolina and New Mexico, who were participating in a study validating physical activity surveys. The survey item was compared with data obtained from MPA recorded in PA records (min/day), Caltrac accelerometers (Muscle Dynamics, Torrance, CA) (kcal/day), and pedometers (steps/day). RESULTS Approximately 64% of the participants reported meeting the MPA recommendation on the survey item. Adjusted analyses showed that those who reported meeting the recommendation were more active than those who reported not meeting the recommendation (109.2 vs. 83.9 min/day, 2171.2 vs. 2088.4 kcal/day, and 5795.7 vs. 4797.2 steps/day, respectively; all p < 0.0001). The types of activities recorded in the PA record did not differ by self-reported adherence to the MPA recommendation except for walking (25.2 vs. 14.0 min/day for those who reported meeting vs. not meeting the recommendation, respectively; p < 0.05). A higher proportion of those who reported meeting the recommendation also reported participating in conditioning activities compared with those who reported not meeting the recommendation (31% vs. 19%, respectively; p < 0.05). CONCLUSIONS The two-part survey item can reliably differentiate between higher and lower levels of activity. Those who perceive themselves as meeting the MPA recommendation are, on average, likely to have higher activity levels than those who perceive that they do not meet the recommendation.