The Influence of Marriage and Cohabitation on Physical Activity Among Middle-Aged and Older People.

Using data from a nationally representative longitudinal study, Midlife in the United States (waves 1-3; N = 1113; aged 49-93), this study investigated whether partnered living status (partnered vs. non-partnered) and partnered living quality (support/strain from partner, partner disagreements) were associated with physical activity in middle-aged/older adults. Regressions were performed to test the effect of change or stability in partnered living status across three waves and relationship quality on the frequency of moderate and vigorous physical activity at Wave 3. Subjects who changed from non-partnered to partnered living had the highest moderate and vigorous physical activity levels. Partner support was positively associated with moderate physical activity (ß = .50, p < .01), and partner disagreement was negatively associated with vigorous physical activity (ß = -.27, p < .01). Results suggest that partnered living status and quality can influence physical activity among the aging population. Physical activity interventions among older adults may benefit from including social support as a key component.

Association of physical activity and sitting time with incident colorectal cancer in postmenopausal women.

Findings from epidemiological studies have found that physical activity (PA) is associated with a lower risk of colorectal cancer (CRC). Recent studies have found an increased CRC risk with higher sitting time (ST); however, many studies did not include PA as a potential confounder. The objective of this project was to investigate the independent and combined associations of ST and PA with the risk of incident CRC, specifically colon and rectal cancer. Participants in the Women's Health Initiative Observational Study (n=74 870), 50-79 years of age self-reported ST and PA at baseline, years 3 and 6. Incident CRC was the primary outcome; colon and rectal cancers were the secondary outcomes, which were centrally adjudicated. Over a 13-year follow-up period, 1145 incident cases of CRC were documented. A positive age-adjusted association was found between higher ST (≥10 vs. <5 h/day) and CRC (P for trend=0.04) and colon cancer (P for trend=0.05); however, these associations were attenuated and no longer significant in multivariable-adjusted models. Compared with inactive women (≤1.7 MET-h/week), the multivariable risk of CRC in the high PA (>20 MET-h/week) group was 0.81 (95% confidence interval: 0.66-1.00; P for trend 0.04). Compared with inactive women with high ST (≥10 h/day), there was a trend toward reduced multivariable CRC risks with higher PA irrespective of ST level (interaction=0.64). We observed an inverse association between leisure time PA and the risk of CRC, particularly for rectal cancer. There was no association between ST and CRC in multivariable models.

Change in Physical Activity and Sitting Time After Myocardial Infarction and Mortality Among Postmenopausal Women in the Women's Health Initiative-Observational Study.

BACKGROUND: How physical activity (PA) and sitting time may change after first myocardial infarction (MI) and the association with mortality in postmenopausal women is unknown. METHODS AND RESULTS: Participants included postmenopausal women in the Women's Health Initiative-Observational Study, aged 50 to 79 years who experienced a clinical MI during the study. This analysis included 856 women who had adequate data on PA exposure and 533 women for sitting time exposures. Sitting time was self-reported at baseline, year 3, and year 6. Self-reported PA was reported at baseline through year 8. Change in PA and sitting time were calculated as the difference between the cumulative average immediately following MI and the cumulative average immediately preceding MI. The 4 categories of change were: maintained low, decreased, increased, and maintained high. The cut points were ≥7.5 metabolic equivalent of task hours/week versus <7.5 metabolic equivalent of task hours/week for PA and ≥8 h/day versus <8 h/day for sitting time. Cox proportional hazard models estimated hazard ratios and 95% CIs for all-cause, coronary heart disease, and cardiovascular disease mortality. Compared with women who maintained low PA (referent), the risk of all-cause mortality was: 0.54 (0.34-0.86) for increased PA and 0.52 (0.36-0.73) for maintained high PA. Women who had pre-MI levels of sitting time <8 h/day, every 1 h/day increase in sitting time was associated with a 9% increased risk (hazard ratio=1.09, 95% CI: 1.01, 1.19) of all-cause mortality. CONCLUSIONS: Meeting the recommended PA guidelines pre- and post-MI may have a protective role against mortality in postmenopausal women.

Effect of prolonged sitting and breaks in sitting time on endothelial function.

UNLABELLED: Sitting time (ST) is associated with cardiovascular disease risk factors, whereas breaking ST has been reported to be beneficial for reducing cardiovascular risk. PURPOSE: The objective of this study is to examine the effects of breaking ST on superficial femoral artery (SFA) endothelial function. HYPOTHESES: 1) Prolonged sitting would induce endothelial dysfunction and changes in shear forces, and 2) breaking ST with brief periods of activity would prevent attenuation in endothelial function. METHODS: Twelve nonobese men (24.2 ± 4.2 yr) participated in two randomized 3-h sitting trials. In the sitting (SIT) trial, subjects were seated on a firmly cushioned chair for 3 h without moving their lower extremities. In the breaking ST trial (ACT), subjects sat similar to the SIT trial but walked on a treadmill for 5 min at 2 mph at 30 min, 1 h 30 min, and 2 h 30 min during the sitting interval. SFA flow-mediated dilation (FMD) was assessed at baseline, 1 h, 2 h, and 3 h in each trial. Statistical analyses were performed using dependent variables SFA FMD and shear rates. Significance was set at P ≤ 0.05. RESULTS: In the SIT trial, there was a significant decline in SFA FMD from baseline to 3 h (baseline, 4.72% ± 3.78%; 1 h, 0.52% ± 0.85%; 2 h, 1.66% ± 1.11%; 3 h, 2.2% ± 2.15; P < 0.05 by ANOVA) accompanied by a decline in mean shear rate and antegrade shear rate but no difference in shear rate (area under the curve). By two-way repeated-measures ANOVA, ACT prevented the sitting-induced decline in FMD (baseline, 4.5% ± 2.3%; 1 h, 5.04% ± 2.85%; 2 h, 5.28% ± 5.05%; 3 h, 6.9% ± 4.5%) along with no decline in shear rates. CONCLUSION: Three hours of sitting resulted in a significant impairment in shear rate and SFA FMD. When light activity breaks were introduced hourly during sitting, the decline in FMD was prevented.

Lower-leg compression, running mechanics, and economy in trained distance runners.

The efficacy of and mechanisms behind the widespread use of lower-leg compression as an ergogenic aid to improve running performance are unknown. The purpose of this study was to examine whether wearing graduated lower-leg compression sleeves during exercise evokes changes in running economy (RE), perhaps due to altered gait mechanics. Sixteen highly trained male distance runners completed 2 separate RE tests during a single laboratory session, including a randomized-treatment trial of graduated calf-compression sleeves (CS; 15-20 mm Hg) and a control trial (CON) without compression sleeves. RE was determined by measuring oxygen consumption at 3 constant submaximal speeds of 233, 268, and 300 m/min on a treadmill. Running mechanics were measured during the last 30 s of each 4-min stage of the RE test via wireless triaxial 10-g accelerometer devices attached to the top of each shoe. Ground-contact time, swing time, step frequency, and step length were determined from accelerometric output corresponding to foot-strike and toe-off events. Gait variability was calculated as the standard deviation of a given gait variable for an individual during the last 30 s of each stage. There were no differences in VO2 or kinematic variables between CON and CS trials at any of the speeds. Wearing lower-leg compression does not alter the energetics of running at submaximal speeds through changes in running mechanics or other means. However, it appears that the individual response to wearing lower-leg compression varies greatly and warrants further examination.

Sitting and endothelial dysfunction: the role of shear stress.

Sedentary activity is a modifiable life-style behavior and a key component in the etiology of atherosclerotic cardiovascular disease (ACVD). US adults and children spend more than half their waking time in sedentary pursuits. Sedentary activity has been shown to result in impaired insulin sensitivity, impaired metabolic function and attenuated endothelial function, which are classic markers of ACVD. Sedentary activity is defined as 'sitting without otherwise being active.' This behavior promotes reduced muscular activity of the lower extremities which decreases leg blood flow, increases blood pooling in the calf, augments mean arterial pressure, and deforms arterial segments resulting in low mean shear stress (SS). SS activates distinct physiological mechanisms which have been proposed to be protective against ACVD; specifically through a SS-induced endothelium-derived nitric oxide mechanism. Reduced bioavailability of nitric oxide creates a pro-oxidant milieu resulting in increased oxidative stress. There is sufficient evidence which demonstrates that endothelial function is attenuated in the presence of oxidative stress. Sedentary activity results in low SS in the lower extremities which may result in increased oxidative stress and impaired endothelial function. This review furthers the use of sitting as model to study the effects of inactivity, discusses possible physiological mechanisms and suggests future directions.

Innovation in weight loss programs: a 3-dimensional virtual-world approach.

BACKGROUND: The rising trend in obesity calls for innovative weight loss programs. While behavioral-based face-to-face programs have proven to be the most effective, they are expensive and often inaccessible. Internet or Web-based weight loss programs have expanded reach but may lack qualities critical to weight loss and maintenance such as human interaction, social support, and engagement. In contrast to Web technologies, virtual reality technologies offer unique affordances as a behavioral intervention by directly supporting engagement and active learning. OBJECTIVE: To explore the effectiveness of a virtual-world weight loss program relative to weight loss and behavior change. METHODS: We collected data from overweight people (N = 54) participating in a face-to-face or a virtual-world weight loss program. Weight, body mass index (BMI), percentage weight change, and health behaviors (ie, weight loss self-efficacy, physical activity self-efficacy, self-reported physical activity, and fruit and vegetable consumption) were assessed before and after the 12-week program. Repeated measures analysis was used to detect differences between groups and across time. RESULTS: A total of 54 participants with a BMI of 32 (SD 6.05) kg/m(2)enrolled in the study, with a 13% dropout rate for each group (virtual world group: 5/38; face-to-face group: 3/24). Both groups lost a significant amount of weight (virtual world: 3.9 kg, P < .001; face-to-face: 2.8 kg, P = .002); however, no significant differences between groups were detected (P = .29). Compared with baseline, the virtual-world group lost an average of 4.2%, with 33% (11/33) of the participants losing a clinically significant (≥5%) amount of baseline weight. The face-to-face group lost an average of 3.0% of their baseline weight, with 29% (6/21) losing a clinically significant amount. We detected a significant group × time interaction for moderate (P = .006) and vigorous physical activity (P = .008), physical activity self-efficacy (P = .04), fruit and vegetable consumption (P = .007), and weight loss self-efficacy (P < .001). Post hoc paired t tests indicated significant improvements across all of the variables for the virtual-world group. CONCLUSIONS: Overall, these results offer positive early evidence that a virtual-world-based weight loss program can be as effective as a face-to-face one relative to biometric changes. In addition, our results suggest that a virtual world may be a more effective platform to influence meaningful behavioral changes and improve self-efficacy.

Using an alternate reality game to increase physical activity and decrease obesity risk of college students.

BACKGROUND: This quasi-experimental study investigated a game intervention--specifically, an alternate reality game (ARG)--as a means to influence college students' physical activity (PA). An ARG is an interactive narrative that takes place in the real world and uses multiple media to reveal a story. METHOD: Three sections of a college health course (n = 115 freshman students) were assigned either to a game group that played the ARG or to a comparison group that learned how to use exercise equipment in weekly laboratory sessions. Pre- and post-intervention measures included weight, waist circumference, body mass index (BMI), percentage body fat (PBF), and self-reported moderate physical activity (MPA) and vigorous physical activity (VPA), and PA (steps/week). RESULTS: A significant group x time interaction (p = .001) was detected for PA, with a significant increase in PA for the game (p < .001) versus a significant decrease (p = .001) for the comparison group. Significant within-group increases for weight (p = .001), BMI (p = .001), and PBF (p = .001) were detected. A significant group x time interaction (p = .001) was detected when analyzing self-reported VPA, with both groups reporting decreases in VPA over time; however, the decrease was only significant for the comparison group (p < .001). No significant group differences were found for MPA. CONCLUSIONS: It is important that any intervention meet the needs and interests of its target population. Here, the ARG was designed in light of the learning preferences of today's college students--collaborative and social, experiential and media-rich. Our results provide preliminary evidence that a game intervention can positively influence PA within the college student population.

Catalyzing transdisciplinary studies in public health: a college health survey and data platform.

Researchers, educators, and service providers recognize that health behaviors and conditions are interdependent, yet they are too often addressed compartmentally. This "silo" approach is unfortunate because it leads to inefficiencies and less effective approaches to prevention. This article describes a process designed to promote better understanding of the interrelatedness of health behaviors and outcomes through a multidimensional Internet-based health survey aimed at undergraduate college students. In addition, we describe a data-sharing platform whereby faculty and students from across disciplines may access the raw data for a variety of uses. An analysis is performed illustrating a syndemic between binge drinking, sexually transmitted diseases, and using alcohol or drugs prior to sexual intercourse. Potential applications of the multidomain survey are discussed, as well as lessons learned and limitations of this approach.

Chocolate milk as a post-exercise recovery aid.

Nine male, endurance-trained cyclists performed an interval workout followed by 4 h of recovery, and a subsequent endurance trial to exhaustion at 70% VO2max, on three separate days. Immediately following the first exercise bout and 2 h of recovery, subjects drank isovolumic amounts of chocolate milk, fluid replacement drink (FR), or carbohydrate replacement drink (CR), in a single-blind, randomized design. Carbohydrate content was equivalent for chocolate milk and CR. Time to exhaustion (TTE), average heart rate (HR), rating of perceived exertion (RPE), and total work (WT) for the endurance exercise were compared between trials. TTE and WT were significantly greater for chocolate milk and FR trials compared to CR trial. The results of this study suggest that chocolate milk is an effective recovery aid between two exhausting exercise bouts.