Federal Physical Activity Guidelines Research Articles

QuickStats: Percentage* of Adults Aged ≥25 Years† Who Met the 2018 Federal Physical Activity Guidelines for Both Muscle-Strengthening and Aerobic Physical Activity,§ by Educational Attainment - United States, 2022.

QuickStats: Percentage* of Adults Aged ≥25 Years† Who Met the 2018 Federal Physical Activity Guidelines for Both Muscle-Strengthening and Aerobic Physical Activity,§ by Educational Attainment - United States, 2022.

Feasibility and preliminary efficacy of a novel web-based physical activity intervention in adults with overweight/obesity: A pilot randomized controlled trial

BackgroundOnly 14% of adults with obesity attain federal guidelines for physical activity (PA), but few interventions address obesity-specific barriers to PA. We designed the web-based Physical Activity for The Heart (PATH) intervention to address this gap. PurposeTest the feasibility and preliminary efficacy of PATH for promoting PA and reducing cardiovascular disease (CVD) risk in adults with overweight/obesity. MethodsIn a 12-week pilot RCT, participants were randomized to PATH (n = 41) or wait-list control (n = 41) groups. Treatment group received access to PATH and met twice/month with a remote coach. The control group received a self-help PA guide and newsletters on general health. Moderate-to-vigorous PA (MVPA) was assessed via Actigraph-GT3X, steps via Fitbit Charge 2™, weight via smart scale, blood pressure (BP) via Omron BP device, and lipids/HbAIC via dry blood spot. Linear mixed modeling examined between- and within-group differences in PA and CVD risk. ResultsThe sample (N = 82) was on average 55.9 ± 8.2 years old; mean BMI 35.5 ± 6.2 kg/m2; 57.3% white and 80.5% female. Recruitment lasted 6-months, and 12-week retention was 96.3%. Treatment group accessed PATH ≥twice/week (92.1%), spent ≥10 min/visit (89.5%) and thought the site was culturally appropriate (79%). At 12 wks, the PATH group had greater mean changes in weekly MVPA (+58.9 vs. +0.9 min, p = .024) and daily steps (+1246.4 vs. -64.2 steps, p = .002) compared to the control group. Also, the PATH group improved in weight, BMI, body fat, waist circumference, and BP (p < .05). ConclusionThe PATH intervention is feasible/acceptable and demonstrated preliminary efficacy for promoting PA among adults with overweight/obesity.

Regular And Habitual Exercisers: Advantages In Heart Rates Of Moderate-intensity Walking

PURPOSE: Based on the Transtheoretical Model (Prochaska & Marcus, 1994), people can be categorized into five exercise stages (ES): ES 1, no exercise, and no intention to change; ES 2, no exercise but considering a change; ES 3, having some change/exercise; ES 4, performing regular exercise recently (less than six months) and meeting Federal Physical Activity Guidelines (FPAG); and ES 5, performing regular exercise habitually (at least six months) and meeting FPAG. This study examined how heart rates (HR) were different during 3.5-mph walking among young adults in different ESs. METHODS: ES was assessed with the Exercise Stages of Change Survey (Marcus & Forsyth, 2009) for 148 university students (66 Females) in the US. Forty-four participants (20 F) were in ESs 2 or 3, forming a Low ES Group (LESG); 47 (20 F) in ES 4, forming a stage-4 group (S4G), and 57 (26 F) in ES 5, forming a stage-5 group (S5G). No participants were in ES 1. Resting HR was assessed for calculating HR reserve (HRR). Further, all participants walked on treadmill at 3.5 mph for three minutes, and HR at the end of the walking was measured with HR monitors (Sigma PC26.14). One-way MANOVA was run to examine differences in HR, maximal HR% (%HRmax), and %HRR at the end of the three-min walking among the three ES groups. RESULTS: No age difference (p > .05) was found among the three ES groups (LESG 21.31 ± 2.32, S4G 21.23 ± 1.67, S5G 21.09 ± 1.11). In contrast, significant differences occurred in all the three HRs in favor of S5G. Specifically, in walking HR, S5G (107.96 ± 13.02) vs. LESG (117.59 ± 14.28), p. < .001; and S5G vs. S4G (115.68 ± 12.76), p < .005. In %HRmax, S5G (54.19 ± 6.48) vs. LESG (59.23 ± 7.09), p. < .001; and S5G vs. S4G (58.19 ± 6.32), p < .005. Finally, in %HRR, S5G (30.30 ± 7.89) vs. LESG (35.63 ± 9.28), p <. 005; and S5G vs. S4G (34.25 ± 8.61), p = .02. CONCLUSIONS: Even among young adults, regular and habitual exercisers (those in S5G) demonstrate significantly lower and healthier HRs in moderate-intensity walking not only than those in LESG, but also than individuals in S4G. Those in S4G, however, fail to show such advantages over LESG people. While both S4G and S5G meet the FPAG, the former has met the FPAG for less than six months, whereas the latter has met the FPAG for at least six months. Only long-time commitment to exercise can result in substantial health benefits.

QuickStats: Age-Adjusted Percentage* of Adults Aged ≥18 Years Who Met the 2018 Federal Physical Activity Guidelines for Both Muscle-Strengthening and Aerobic Physical Activity,† by Urbanization Level§ - National Health Interview Survey, United States, 2020¶.

QuickStats: Age-Adjusted Percentage* of Adults Aged ≥18 Years Who Met the 2018 Federal Physical Activity Guidelines for Both Muscle-Strengthening and Aerobic Physical Activity,† by Urbanization Level§ - National Health Interview Survey, United States, 2020¶.

Abstract P073: Does Physical Activity Modify The Association Between High-density Lipoprotein Cholesterol And All-cause Mortality?

Introduction: There is well-known inverse dose-response relationship between high-density lipoprotein cholesterol (HDL-C) and cardiovascular disease and all-cause mortality. However, only recently is the entire spectrum of HDL-C being examined with mortality. A similar dose-response relationship with mortality exists with physical activity (PA). Engaging in regular PA has consistently been shown to lower both CVD and all-cause mortality by 20-30%. This study examined the association between HDL-C and mortality by PA categories created around the current federal PA guidelines for United States Adults. Hypothesis: Level of PA participation will modify mortality risk across a spectrum of HDL-C levels. Methods: The study sample (n=8,535) included participants (age 20-79 years) from the 1999-2006 National Health and Nutrition Examination Survey. PA was classified into three distinct categories: Those meeting neither of the PA guidelines (category 1), those meeting only the aerobic PA guideline (category 2), and those meeting both the aerobic PA and muscular strengthening activity guidelines (category 3). HDL-C was categorized into eight groups (≤30, 31-40, 41-50, 51-60 [referent group], 61-70, 70-80, and &gt;80 mg/dL). All-cause mortality served as the dependent variable in this study. Cox proportional hazard models were used for all analyses. Results: Among those in PA category 1, a statistically significant increase in all-cause mortality risk was found for those with an HDL-C of 71-80 (HR 1.94, 95% CI 1.14-3.32) and &gt;80 mg/dL (HR 2.18, 95% CI 1.25-3.79). In those with an HDL-C &lt;30 mg/dL, a borderline significant increase in all-cause mortality risk was found (HR 1.67, 95% CI 0.96-2.89, p=0.06) Among those in PA categories 2 and 3, no significant increases in all-cause mortality risk were found. Conclusions: Results suggest that meeting at least the aerobic PA guideline mitigates the increased risk for all-cause mortality in those with very high HDL-C and potentially very low HDL-C. Future studies are warranted to investigate the effects of PA on mortality across measures of HDL-C.

Health-promoting behaviors in the United States during the early stages of the COVID-19 pandemic

The potential negative effects of the COVID-19 pandemic on health-compromising behaviors including overeating, processed food intake, and alcohol use have been well documented. However, it is possible the COVID-19 pandemic has had positive effects on some health-promoting behaviors like cooking and fruit and vegetable intake. The current study was a preregistered secondary data analysis using data from a U.S. national, crowdsourced study (n = 868) on eating behaviors during the early stages of the COVID-19 pandemic. The objectives of the current study were to compare levels of cooking, fruit and vegetable intake, and physical activity among U.S. adults during the early stages of the COVID-19 pandemic to pre-pandemic levels in reference groups of U.S. adults, and test whether subjective stress from the pandemic was associated with health-promoting behaviors by obesity status. During the early stages of the COVID-19 pandemic, participants cooked more often and ate 0.23 more cups of fruits and vegetables per day, but 28.8% fewer participants met federal physical activity guidelines. Greater COVID-19 stress was minimally to moderately associated with greater cooking, fruit and vegetable intake, and physical activity. The positive association between COVID-19 stress and fruit and vegetable intake was stronger for individuals with obesity. The COVID-19 pandemic might have encouraged U.S. adults, especially those at risk for complications, to engage in some health-promoting behaviors while creating barriers for other behaviors.

Medical Student Knowledge Of The Federal Physical Activity Guidelines

PURPOSE: The purpose of this study is to assess medical student knowledge of the 2008 Health People Federal Physical Activity Guidelines. METHODS: 254 Medical Students completed a voluntary survey assessing knowledge of the 2008 Healthy People Federal Physical Activity Guidelines. RESULTS: Of the 254 respondents, 38% of respondents correctly knew the adult aerobic PA guidelines, 72.44% correctly identified the adult muscle strength PA guidelines, 31.10% correctly identified guidelines for pediatric aerobic PA guidelines, 55.12% correctly identified the pediatric muscle and bone strength PA guidelines and 24.80% of respondents correctly identified a form of vigorous physical activity amongst a list of moderate physical activities. Amongst the 254 survey respondents, 201 gave examples of how they incorporate physical activity into their lives, 26% of the responses included solely exercise examples. Walking to work/class was the most common non-exercise response. CONCLUSIONS: Medical student knowledge of federal physical activity guidelines and the difference between physical activity and exercise is lacking. More emphasis on PA guidelines in medical education curriculum could enhance medical student knowledge and ultimately influence future patient education, health and wellness.

Physical activity habit formation through a technology-based program.

Only about half of adults in the United States meet the minimum federal guidelines for physical activity (PA), with less than one quarter getting an optimal amount of weekly activity. Programs to increase PA can improve health and increase worker productivity. Clinic patients of a nurse practitioner-run employee health clinic in a self-insured health care system experienced health conditions associated with insufficient PA and wanted to form habits of adequate PA for health promotion. A quantitative design was used to assess pre- and postintervention measures in this quality improve project. Patients of the clinic enrolled in a technology-based 3-month PA habit development program that included wearable technology, tracked step counts, daily text messaging, and weekly electronic newsletters. Biometric and habit measures were taken at baseline and at the conclusion of the 3-month program to determine effectiveness. Participants who completed the program developed strong habits of PA, on average. Small improvements in blood pressure, weight, and body mass index occurred but were not clinically significant. Two thirds of participants dropped out, which was fewer than anticipated based on prior reports. Habits make an activity less difficult to continue than to stop. Thus, PA habits developed through this innovative intervention should persist and lead to decreased risk of conditions such as diabetes, heart disease, cancers, and dementia. The self-insured employer should reap the benefits of employee's PA through increased productivity, decreased absenteeism, and lower health care costs.

A Randomized Community-based Exercise Training Trial in African American Men: Aerobic Plus Resistance Training and Insulin Sensitivity in African American Men.

To examine the impact of a community-based exercise training intervention on cardiometabolic outcomes in African American men who have a family history of type 2 diabetes. The Aerobic Plus Resistance Training and Insulin Sensitivity in African American Men (ARTIIS) study randomized participants into either an exercise training intervention or an information only control group for 5 months. The exercise training intervention consisted of 150 min of moderate intensity aerobic activity and 2 d of resistance training per week, consistent with the current federal physical activity guidelines. Participants in the control group received monthly newsletters featuring topics focused heavily on type 2 diabetes education and prevention. Outcome data were analyzed using repeated-measures ANCOVA models and incorporating both intention-to-treat and per-protocol principles. Adherence to the aerobic and resistance training prescriptions were between 77% and 79%. Despite significant within group improvements in glucose and insulin levels (fasting, 2 h, 2 h minus baseline) and Homeostatic Model 2-Insulin Resistance, there were not significant between group differences. There was a marginally significant between group difference for Homeostatic Model 2-Beta (P < 0.06), and significant between group differences in peak cardiorespiratory fitness (P < 0.001) and waist circumference (P = 0.03). These findings suggest that exercise training in accordance with the current national recommendations is effective in improving some health parameters in middle-age African American men who have a family history of type 2 diabetes, but did not have a significant impact on glycemic status.

The Association of Physical Activity and Mortality Risk Reduction Among Smokers: Results From 1998-2009 National Health Interview Surveys-National Death Index Linkage.

The mortality benefits of meeting the US federal guidelines for physical activity, which includes recommendations for both aerobic and muscle-strengthening activities, have never been examined among smokers. Our aim was to investigate the association between reporting to meet the guidelines and all-cause, cancer, cardiovascular disease, and respiratory disease mortality among smokers. We pooled data from the 1998-2009 National Health Interview Survey, which were linked to records in the National Death Index (n = 68,706). Hazard ratios (HR) were computed to estimate the effect of meeting the physical activity guidelines on mortality. Smokers who reported meeting the guidelines for physical activity had 29% lower risk of all-cause mortality (HR: 0.71; 95% confidence interval [CI], 0.62-0.81), 46% lower risk of mortality from cardiovascular disease (HR: 0.54; 95% CI, 0.39-0.76), and 26% lower risk of mortality from cancer (HR: 0.74; 95% CI, 0.59-0.93), compared with those who reported meeting neither the aerobic nor the muscle-strengthening recommendations of the guidelines. Meeting the aerobic recommendation of the guidelines was associated with a 42% decline in that risk (HR: 0.58; 95% CI, 0.44-0.77). Smokers who adhere to physical activity guidelines show a significant reduction in mortality.

Older Veterans EmpoweRed To Use Regular Exercise (OVERTURE) II: Design and methods of a randomized controlled trial among older veterans with chronic health conditions

There are physical and mental health benefits associated with regular physical activity across the life span [1]; however, individuals are less likely to engage in regular physical activity with advancing age. Recent statistics from the Federal Interagency Forum on Aging Related-Statistics (FIFA-RS) [2] suggest that only 12% of adults 65 years and older engage in regular physical activity that meets the Federal guidelines for physical activity. The guidelines recommend that U.S. adults engage in at least 150 min of moderate-intensity aerobic activity weekly and two to three alternating days of muscle-strengthening activities [3,4]. The guidelines further recommend that older adults with chronic health conditions strive to be as physically active as possible. Among older adults, veterans represent a special population that may not be able to meet the Federal government's guidelines for physical activity. As a result of military service, older veterans who once were considered to be in optimal physical and mental condition as active duty service members, often live with multiple chronic conditions (MCCs) that may limit physical activity [5,6]. For example, older veterans receiving care through the Veterans Affairs (VA) often report a high degree of functional limitations and mental health issues [5,6], such as chronic knee and back pain [7], major depression [8], and post-traumatic stress disorder [8]. Consequentially, the presence of MCCs increases the risk for poor quality of life (QOL) [9,10] and wellbeing (WB) [11] and limits physical activity. In spite of the evidence that physical activity is beneficial to QOL [9] and WB [11], there is scant evidence in the research literature of exercise interventions for older adults with MCCs, specifically for older veterans. Older adults, regardless of veteran status, who have MCCs are often excluded from exercise interventions [12]. OVERTURE II endeavors to determine the feasibility of an exercise intervention that may promote QOL and WB among older veterans with MCCs.

Muscle-strengthening physical activity is associated with cancer mortality: results from the 1998-2011 National Health Interview Surveys, National Death Index record linkage.

To examine the association of muscle-strengthening activities (MSA) and cancer mortality. We pooled data from the 1998 to 2009 National Health Interview Survey (NHIS), which were linked to records in the National Death Index. Mortality follow-up was through 31 December 2011. Based on U.S. federal guidelines for physical activity, we dichotomized MSA and compared those who performed MSA twice a week or more to others with lower MSA. We also examined dose-response relationship of MSA frequency with cancer mortality. Hazard ratios (HR) from Cox regression were computed to estimate the association of MSA with the risk of cancer mortality. Mean follow-up was 7.9years and the analysis sample size was 310,282. Covariate-adjusted results showed that meeting the MSA guideline was associated with a 19% lower risk of cancer mortality (HR 0.81, 95% CI 0.73, 0.90). We found no evidence of a dose-response relationship between the frequency of performing MSA and cancer mortality. Adhering to the U.S. federal guideline for MSA is associated with lower cancer mortality. Public health programs and policy for cancer prevention and control should promote MSA to further reduce cancer mortality.

Demographic-specific Validity of the Cancer Prevention Study-3 Sedentary Time Survey.

This study examined the 1-yr test-retest reliability and criterion validity of sedentary time survey items in a subset of participants from a large, nationwide prospective cohort. Participants included 423 women and 290 men age 31 to 72 yr in the Cancer Prevention Study-3. Reliability was assessed by computing Spearman correlation coefficients between responses from prestudy and poststudy surveys. Validity was assessed by comparing survey-estimated sedentary time with a latent variable representing true sedentary time estimated from the 7-d diaries, accelerometry, and surveys through the method of triads. Sensitivity analyses were restricted to 566 participants with an average of 14+ h of diary and accelerometer data per day for 7 d per quarter. Reliability estimates for total sitting time were moderate or strong across all demographic strata (Spearman ρ ≥ 0.6), with significant differences by race (P = 0.01). Reliability estimates were strongest for the TV-related sedentary time item (Spearman ρ, 0.74; 95% confidence interval, 0.70-0.77). The overall validity coefficient (VC) for survey-assessed total sedentary time was 0.62 (95% confidence interval, 0.55-0.69), although VC varied by age group and activity level (P < 0.05). However, VC were similar across groups (P < 0.05) when restricting to highly compliant participants in a sensitivity analysis. The Cancer Prevention Study-3 sedentary behavior questionnaire has acceptable reliability and validity for ranking or categorizing participants according to sedentary time. Acceptable reliability and validity estimates persist across various demographic subgroups.

Exercise

Numerous observational studies have demonstrated an inverse relationship between physical activity and risk of many chronic illnesses. The protective effect of exercise is strongest against coronary artery disease, hypertension, stroke, type 2 diabetes mellitus, obesity, anxiety, depression, osteoporosis, and cancers of the colon and breast. Despite these proven benefits, only 25% of adults in the United States exercise at recommended levels. Globally, physical inactivity is the fourth leading risk factor for death, followed by overweight and obesity. This module describes exercise physiology, including cardiovascular response to dynamic exercise, pulmonary response, musculoskeletal response, metabolic effects, effects on blood lipid levels, hematologic effects, effects on vascular inflammation, effects on body fluids, and psychological effects. Exercise and the elderly and the relationship between exercise and longevity are reviewed. Prescribing exercise and complications of exercise are also discussed. Tables describe the categories of patients screened for possible coronary artery disease, exercise time required to consume 2,000 kcal, and exercise advice for patients. Figures include a graph showing the number of adults who met the federal physical activity guidelines criteria, the top 10 global risk factors for death in 2004, the process of providing energy for the muscle, and trends in physician prescriptions for exercise. This module contains 4 highly rendered figures, 3 tables, 35 references, and 5 MCQs.

Physical Activity Guideline Adherence and Physical Fitness

Encouraging regular physical activity (PA) is a major public health objective in the United States for several reasons, including the promotion of physical fitness. As such, the first edition of federal Physical Activity Guidelines for Americans (PAG) was released in 2008. For youth, these PAG include recommendations for aerobic and muscle- strengthening (MS) activity. PURPOSE: To examine the association between adherence to PAG and physical fitness in a nationally-representative sample of children and adolescents. METHODS: The NHANES National Youth Fitness Survey (NNYFS) collected fitness test and PA questionnaire data on children and adolescents (ages 3-15 years, n = 1,576). Fitness testing was completed for the plank (3-15 years), modified pull-up (5-15 years), handgrip strength (6-15 years), and aerobic fitness (12-15 years) by trained test administrators. Fitness test results were converted into age-specific percentile scores. All subjects reported the number of previous days of the week that included 60 minutes of PA, while 12-15 year olds also reported the number of previous days that included MS activities. Independent t-tests were used to compare the mean physical fitness percentile of youth reporting 7 days of 60 minutes of PA to those reporting ≤ 6 days and adolescents reporting 2 or more days of muscle-strengthening activity to those reporting ≤ 1 day. RESULTS: Youth reporting 7 days/week of PA had a higher mean relative grip strength (53.8 vs. 46.8 percentile), modified pull-up (53.7 vs. 47.1 percentile), and VO2max (48.9 vs. 40.8 percentile) compared to those with ≤ 6 days/week (all p < 0.05). Those participating in MS activity 2 days/week had a higher relative grip strength (54.7 vs. 45.3 percentile), modified pull-up (54.2 vs. 46.8 percentile), plank (54.5 vs. 44.4 percentile), and VO2max (45.7 vs. 39.8 percentile) compared to the ≤ 1 day/week group (all p < 0.05). CONCLUSION: In this nationally-representative sample, meeting PAG’s were associated with measures of aerobic capacity, muscular strength, and muscular endurance. Future prospective research is needed to investigate the impact of changing PA level to meet (or not meet) the PAG on physical fitness.

College Health Students’ Knowledge and Perceptions of Exercise Benefits and Dysfunctional Exercise

Background and Purpose: A high percentage of people fail to meet the federal Physical Activity Guidelines while some adults develop dysfunctional exercise. The applications of Self-Determination Theory (SDT) in the field of physical activity suggest that how people are motivated to exercise can lead to different outcomes, such as dysfunctional exercise. Adequate training for health promotion professionals can ensure their competency in successfully promoting healthy exercise. This study assessed the knowledge and perceptions regarding exercise benefits and dysfunctional exercise among Kinesiology and Community Health students—the future health professionals. Methods: A crosssectional study was conducted in a convenience sample of 183 participants from a public university in the northwest region. Results: Both Kinesiology and Community Health majors demonstrated a low level of knowledge regarding dysfunctional exercise, and were inclined to cite controlled rather than autonomous benefits for exercise engagement. Conclusion: Program curriculum changes, such as the coverage of dysfunctional exercise and Self-Determination Theory, should be considered to address the issue.

Do Inactive Older Adults Who Increase Physical Activity Experience Less Disability: Evidence From the Osteoarthritis Initiative.

Physical inactivity is a leading risk factor for developing disability. Although randomized clinical trials have demonstrated improving physical activity can reduce this risk in older adults with arthritis, these studies did not specifically evaluate inactive adults. The aim of this study was to evaluate the relationship of changes in physical activity with disability changes among initially inactive adults with or at high risk of knee osteoarthritis from Osteoarthritis Initiative. Inactive persons were identified at baseline based on the US Department of Health and Human Services classification (no [zero] 10-minute session of moderate-to-vigorous [MV] activity over 1 week) from objective accelerometer monitoring. Two years later, physical activity change status was classified as follows: (1) met Federal physical activity guidelines (≥150 MV minutes/week acquired in bouts ≥10 minutes), (2) insufficiently increased activity (some but <150 MV bout minutes/week), or (3) remained inactive. Disability at baseline and 2 years was assessed by Late Life Disability Instrument limitation and frequency scores. Multiple regression evaluated the relationship of physical activity change status with baseline-to-2-year changes in disability scores adjusting for socioeconomics, health factors, and baseline disability score. Increased physical activity showed a graded relationship with improved disability scores in Late Life Disability Instrument limitation (P < 0.001) and frequency scores (P = 0.027). While increasing MV activity to guideline levels showed the greatest reduction, even insufficiently increased physical activity was related to reduced disability. Findings support advice to increase MV physical activity to reduce disability among inactive adults with or at high risk of knee osteoarthritis, even when guidelines are not met.

Invited Commentary: Little Steps Lead to Huge Steps-It's Time to Make Physical Inactivity Our Number 1 Public Health Enemy.

The analysis plan and article in this issue of the Journal by Evenson et al. (Am J Epidemiol 2016;184(9):621-632) is well-conceived, thoughtfully conducted, and tightly written. The authors utilized the National Health and Nutrition Examination Survey data set to examine the association between accelerometer-measured physical activity level and mortality and found that meeting the 2013 federal Physical Activity Guidelines resulted in a 35% reduction in risk of mortality. The timing of these findings could not be better, given the ubiquitous nature of personal accelerometer devices. The masses are already equipped to routinely quantify their activity, and now we have the opportunity and responsibility to provide evidenced-based, tailored physical activity goals. We have evidenced-based physical activity guidelines, mass distribution of devices to track activity, and now scientific support indicating that meeting the physical activity goal, as assessed by these devices, has substantial health benefits. All of the pieces are in place to make physical inactivity a national priority, and we now have the opportunity to positively affect the health of millions of Americans.

QuickStats: Percentage of U.S. Adults Who Met the 2008 Federal Physical Activity Guidelines for Aerobic and Strengthening Activity,* by Sex - National Health Interview Survey,(†) 2000-2014.

The percentage of U.S. adults who met the 2008 federal physical activity guidelines for Americans increased from 15.1% in 2000 to 21.5% in 2014. Most of the increase occurred from 2006 to 2010 for men and from 2007 to 2011 for women. During all years, men were more likely than women to meet the physical activity guidelines. In 2014, 25.5% of men and 17.7% of women met the guidelines.

Physical activity metrics to predict function in older adults with lower extremity conditions: The Osteoarthritis Initiative

Purpose: Federal physical activity guidelines (moderate or vigorous activity acquired in bouts lasting at least 10 minutes {MV-bout] ≥150 minutes/week) are grounded in studies showing cardiovascular benefits. For adults with lower extremity conditions, maintaining-high or improving-low function may be a more immediate concern than cardiovascular health. The objective of this study is to evaluate if there are 1) Alternative physical activity metrics to consider for Persons who Maintain-high or Improve-low Lower Extremity (PerMILE) function, in contrast to the MV-bout metric which registers zero for a large portion of these adults and 2) Dosage related to subsequently improving-low or maintaining-high function among adults with lower extremity joint conditions. Methods: This longitudinal study evaluates adults with symptomatic (pain/aching/stiffness) or radiographic evidence of lower extremity joint conditions who participated in an accelerometer monitored physical activity substudy of the Osteoarthritis Initiative (OAI). Gait speed (n=1476) and self-reported SF-12 physical component score (PCS) function (n=1629) were measured at the substudy baseline (OAI 48 month clinical visit) and two years later. Good PerMILE function was separately determined for each measure based on staying in the best (i.e., maintaining-high) or moving to a better (i.e., improving-low) 2-year function quintile compared to baseline. To identify alternative metrics to predict good PerMILE function, the area under the receiver operating curve (AUC) from alternative physical activity metrics (sedentary, light intensity activity, all MV activity [All-MV], and all non-sedentary minutes/week) were compared to the reference MV-bout metric AUC. Classification tree analysis was used to identify metric minimum dosage thresholds which predict good PerMILE function. Results: This study evaluated adults aged 40–83 with baseline lower extremity conditions, of whom 34% and 38% had good 2-year PerMILE gait speed and SF-12 PCS function, respectively. All-MV weekly activity was the only metric investigated with significantly stronger predictive ability for good PerMILE function in both gait speed AUC (difference 0.05, 95% CI: 0.03, 0.07) and SF-12 PCS (difference: 0.02, 95% CI: 0.001, 0.03)assessments compared to the federal guideline MV-bout metric AUC (Table). Among adults with lower extremity conditions, doing at least 45 All-MV activity minutes per week had odds of 2.9 (95% CI: 2.4 to 3.6) for good PerMILE gait speed function compared to those with less All-MV activity. Adults doing at least 47 minutes All-MV activity minutes per week had odds of 1.9 (95% CI: 1.6 to 2.3) of good PerMILE SF-12 function compared to those with less. Conclusions: All MV activity (All-MV) minutes/week is a better metric than the traditional MV-bout metric to predict good PerMILE function for adults with lower extremity conditions. These findings support a minimum physical activity dose of at least 50 total MV minutes each week to subsequently maintain high function or improve low function.Tabled 1Table. Evaluation of Physical Activity Metrics to Predict Good PerMILE* FunctionGood 2-year PerMILE Gait Speed (n=1476)Physical Activity MetricArea Under Receiver Operating Curve (AUC) (95% CI)Metric AUC Compared to Reference (MV-bout) AUC Difference (95% CI)p-valueMV-bout time0.60 (0.57, 0.63)ReferenceSedentary time0.50 (0.47, 0.53)−0.09 (−0.14, −0.05)<.01Light activity time0.55 (0.52, 0.58)−0.05 (−0.09, −0.01)0.01All MV time0.65 (0.62, 0.67)0.05 (0.03, 0.07)<.01Non-sedentary time0.57 (0.54, 0.60)−0.02 (−0.06, 0.01)0.18Good 2-year PerMILE SF12 PGood 2-year PerMILE SF12 Physical Activity Component Score (n=1629)MV-bout time0.57 (0.54, 0.60)ReferenceSedentary time0.50 (0.47, 0.53)−0.07 (−0.12, −0.03)<.01Light activity time0.52 (0.49, 0.55)−0.05 (−0.09, −0.01)<.01All MV time0.59 (0.56, 0.62)0.02 (0.001, 0.03)0.03Non-sedentary time0.54 (0.51, 0.56)−0.03 (−0.07, −0.001)0.04*Persons who Maintain-high or Improve-low Lower Extremity. Open table in a new tab *Persons who Maintain-high or Improve-low Lower Extremity.