Hours Of Vigorous Activity Research Articles

Physical activity and depression in men: Increased activity duration and intensity associated with lower likelihood of current depression

ObjectivesDepression is a significant public health issue for men, however men are less likely to use mental health services. Alternative interventions, such as physical activity, may be of value for this population. This study sought to determine what levels and intensity of physical activity are associated with lower depression prevalence in Australian men. MethodsUsing baseline data from 13,884 participants in the Australian Longitudinal Study on Male Health we compared current depression in men who completed the recommended 150 min of physical activity in the past week with men who did not. Duration of activity was examined using logistic regression with restricted cubic splines. Intensity of physical activity was examined by isotemporal substitution of hours of moderate activity with hours of vigorous activity. ResultsMen who completed at least 150 min/week of activity had lower odds of moderate/severe depression symptoms. Duration of activity was inversely associated with moderate/severe depression symptoms. Among physically active men, each additional hour of moderate activity replaced with vigorous activity was associated with lower odds of depression. LimitationsThis is a cross-sectional study and so cannot determine causal direction in the relationship between physical activity and depression symptoms observed. Self-report measures of physical activity are widely used but are not as accurate as biometric measurement. ConclusionsIn adult men, meeting minimum recommendations is associated with lower current depression. Increased duration and greater intensity of activity were both associated with further reduction in prevalence. Promoting higher levels of physical activity is potentially an intervention for improving men's mental wellbeing.

Wearables data integration: Data-driven modeling to adjust for differences in Jawbone and Fitbit estimations of steps, calories, and resting heart-rate

Differences in data output from two leading devices in the consumer-grade wearables market have been examined, namely Jawbone UP4 and Fitbit Charge HR devices, by comparing measurements that were conducted while participants wore both devices in tandem. Aggregate daily totals of steps and calories were shown to be highly correlated between devices (0.82–0.93 correlation coefficient for steps and 0.71–0.85 for calories); however, at the hourly level, differences in data output are evident, especially during hours of vigorous activity. These differences lead to both under- and over-estimation of measures such as hourly step-counts. Heart rate measurement with Jawbone and Fitbit is shown to be significantly different even at the daily level (p-value<0.00001), which could be due to hardware differences in sensor type and possibly due to unknown differences in proprietary algorithms. Models were trained to enable adjustment of data collected from one device to the equivalent value in terms of the other device’s measurement. This approach to data integration is recommended for researchers who are comparing data from multiple wearable devices, for individual users who have switched from one device to another and could use this method to adjust their wearables data history to be comparable with the new device, or for users who are comparing data with a user who has another type of device, or for groups organizing fitness challenges and health initiatives that can track users by comparing diverse wearables data.

Impacts of Body Mass Index, Physical Activity, and Smoking on Femoral Bone Loss: The Tromsø Study

Bone mineral density (BMD) is a reflection of bone strength and lifestyles that preserve bone mass and may reduce fracture risk in old age. This study examined the effect of combined profiles of smoking, physical activity, and body mass index (BMI) on lifetime bone loss. Data were collected from the population-based Tromsø Study. BMD was measured as g/cm(2) by dual-energy X-ray absorptiometry (DXA) at the total hip and femoral neck in 2580 women and 2084 men aged 30 to 80 years in the 2001-02 survey, and repeated in 1401 women and 1113 men in the 2007-08 survey. Height and weight were measured and lifestyle information was collected through questionnaires. Data were analyzed using linear mixed models with second-degree fractional polynomials. From the peak at the age around 40 years to 80 years of age, loss rates varied between 4% at the total hip and 14% at femoral neck in nonsmoking, physically active men with a BMI of 30 kg/m(2) to approximately 30% at both femoral sites in heavy smoking, physically inactive men with a BMI value of 18 kg/m(2) . In women also, loss rates of more than 30% were estimated in the lifestyle groups with a BMI value of 18 kg/m(2) . BMI had the strongest effect on BMD, especially in the oldest age groups, but a BMI above 30 kg/m(2) did not exert any additional effect compared with the population average BMI of 27 kg/m(2) . At the age of 80 years, a lifestyle of moderate BMI to light overweight, smoking avoidance, and physical activity of 4 hours of vigorous activity per week through adult life may result in 1 to 2 standard deviations higher BMD levels compared with a lifestyle marked by heavy smoking, inactivity, and low weight. In the prevention of osteoporosis and fracture risk, the effect of combined lifestyles through adult life should be highlighted. © 2014 American Society for Bone and Mineral Research.

Associations among Body Mass Index, Waist Circumference, and Health Indicators in American Indian and Alaska Native Adults

Little is known about obesity-related health issues among American Indian and Alaska Native (AIAN) populations. A large cohort of AIAN people was assembled to evaluate factors associated with health. The study was conducted in Alaska and on the Navajo Nation. A total of 11,293 AIAN people were included. We present data for body mass index (BMI, kg/m2) and waist circumference (cm) to evaluate obesity-related health factors. Overall, 32.4% of the population were overweight (BMI 25-29.9 kg/m2), 47.1% were obese (BMI > or = 30 kg/m2), and 21.4% were very obese (BMI, > or = 35 kg/m2). A waist circumference greater than 102 cm for men and greater than 88 cm for women was observed for 41.7% of men and 78.3% of women. Obese people were more likely to perceive their health as fair/poor than nonobese participants (prevalence ratio [PR], 1.91; 95% CI, 1.71-2.14). Participants younger than 30 years were three times more likely to perceive their health as being fair or poor when their BMI results were 35 or greater compared with those whose BMI results were less than 25 kg/m2. A larger BMI was associated with having multiple medical conditions, fewer hours of vigorous activity, and more hours of television watching. Given the high rates of obesity in AIAN populations and the association of obesity with other health conditions, it is important to reduce obesity among AIAN people.

Physical Activity and Colorectal Cancer

Physical activity has been shown to reduce risk of colon cancer. Some studies have shown site-specific associations while others have not. The inverse association between physical activity and colon cancer is consistent although only 7 of 13 studies that have collected both colon and rectal cancer data in the same manner report reduced risk for rectal cancer; four of these studies detected statistically significant inverse associations. The frequency, duration and intensity of activity are important components of a public health message to reduce risk of colon cancer through performance of physical activity. However, difficulties in estimating the exact amount of activity needed and frequency and intensity of activity result in only crude estimates of dose needed for a protective effect. Much of the literature suggest that more intense activity is needed to reduce colon cancer risk and that somewhere between 3.5 and 4 hours of vigorous activity per week may be needed to optimise protection. Several biological mechanisms have been proposed to explain the association between physical activity and colon cancer; many of these mechanisms also support the observation that intense activities are most protective. Biological mechanisms include: physical activity increasing gut motility; enhancing the immune system; decreasing insulin and insulin-like growth factor levels; decreasing obesity; enhancing free radical scavenger systems; and influencing prostaglandin levels. The evidence taken together provides strong support for lack of physical activity being causally related to colon cancer. It has been estimated that 12-14% of colon cancer could be attributed to lack of frequent involvement in vigorous physical activity.