Moderate to vigorous training combined with longer lifespan

Relation

Lee I, Shiroma E, Evenson K, Kamada M, LaCroix A and Buring J. Accelerometer-measured physical activity and sedentary behavior in relation to all-cause mortality: The Women's Health Study.Traffic. 2018;137:203-205.

Objective

To assess the association between type and amount of physical activity and longevity in women.

Draft

Prospective cohort study

Participant

The study involved 17,708 women (mean age 72, standard deviation 5.7 years) recruited from the Women's Health Study (WHS); All women enrolled were able to leave the house without assistance. Participants were given a three-axis accelerometer (ActiGraph GT3X+) to wear for 7 days, with a minimum requirement of wearing it for at least 10 hours per day for at least 4 days. After excluding faulty devices and noncompliance with use, data from 16,741 women were analyzed.

Study parameters assessed

Using data from the ActiGraph GT3X+, investigators calculated the total volume of physical activity in minutes per day. Activity was categorized based on accelerometer counts per minute: sedentary with less than 200 counts per minute, light physical activity (LPA) between 200 and 2,689 counts per minute, and moderate to vigorous physical activity (MVPA) with 2,690 counts per minute or more. Participants were stratified into quartiles based on minutes per day of total physical activity, sedentary behavior, LPA, and MVPA.

This research is a reminder that small changes must transition into at least moderate-intensity training to truly benefit longevity.

Researchers also collected information on smoking status, alcohol consumption, diet composition, use of hormone therapy, personal history of cancer or cardiovascular disease, and family history of myocardial infarction or cancer via self-reports and, when possible, medical records.

Data were analyzed using proportional hazards regression models.

Primary outcome measures

The primary endpoint of the study was mortality, as determined from medical records, death certificates, or the National Death Index. Participants were enrolled between 2011 and 2015, and mortality was assessed through December 31, 2015. The average follow-up time was 2.3 years.

Key insights

During the course of the study, 207 of the 16,741 women included in the study died. Two models were used to analyze the hazard ratios between activity and mortality: Model 1, adjusted for age and accelerometer wear time, and Model 2, adjusted for potential confounders related to lifestyle and personal and family health history.

Strong inverse associations between total activity and mortality have been identified (P=0.002) and MVPA and mortality (P=0.0002) analyzing Model 1 and Model 2. The magnitude of risk reduction between the highest and lowest activity quartiles was approximately 60% to 70%.

An inverse association was observed between LPA and mortality (P=0.04), but after adjusting for potential confounders in Model 2, the association was no longer statistically significant (P=0.82). Similarly, a link between sedentary behavior and increased mortality has been found (P=0.007), but statistical significance was lost when adjusting for confounders (P=0.99).

The researchers concluded that physical activity is beneficial for longevity and that this benefit largely comes from MVPA.

Practice implications

This research complements the evidence used to develop the physical activity guidelines issued by the United States Office of Disease Prevention and Health Promotion (ODPHP). Until recently, the studies used to develop these guidelines relied on self-reports of moderate and vigorous physical activity. The advent of activity measurement devices allows for the detection and analysis of the effects of lighter physical activity, as well as more accurate assessment of moderate and vigorous activity.

According to this study, exercise appears to help people live longer. While this data isn't exactly earth-shattering, it does show a more dramatic benefit than previous research that used a self-report model of activity (approximately 60% to 70% vs. 30% to 40% risk reduction when comparing the most active people). among the least active).¹It also suggests that light activity alone is not enough to achieve this benefit and confirms current guidelines published by the ODPHP and the World Health Organization.^2.3

Current physical activity guidelines recommend that adults do at least 150 minutes of moderate-intensity exercise or 75 minutes of vigorous exercise per week, as well as resistance training exercises 2 or more days per week. Training intensity can be assessed clinically using the Borg Rating of Perceived Exertion (RPE) scale or target heart rate zones.^4.5The Borg scale ranges from 0 (lying in bed) to 20 (sprinting as fast as possible); Moderate intensity activity corresponds to 11-14 on the scale, and vigorous activity corresponds to 17-19 on the scale. In the heart zone model, moderate exercise is 50% to 70% of maximum heart rate and vigorous exercise is 70% to 85% of maximum heart rate, with the maximum heart rate estimated at 220 minus the person's age in years.

According to the 2016 National Health Interview Survey (NHIS), only 51.7% of adults in the United States achieve the recommended amount of aerobic exercise.⁶Inactivity is a modifiable risk factor for the morbidity and mortality of chronic diseases,¹and it is receiving renewed attention in popular culture (e.g., with “sitting is the new smoking,” a phrase popularized by Dr. James Levine of the Mayo Clinic).⁷As a healthcare provider, it can be difficult to motivate patients to exercise. Given the disappointing adherence to current guidelines, a didactic approach does not appear to be effective for many individuals. Therefore, it is the responsibility of providers to adapt and develop alternative strategies to promote lifestyle changes in those who do not respond to simply being told current guidelines.

In naturopathy, longer visits and the stronger relationships they can foster provide a unique advantage in promoting lifestyle improvements. The specific benefits of physical activity for the individual can be discussed in detail, obstacles to change can be identified, individual motivations for more exercise can be identified, favorite movements can be identified and goals can be developed together. For some patients, small steps are necessary. However, this research is a reminder that small changes need to be translated into at least moderate-intensity training to truly benefit longevity. So take a brisk walk.

This study was strengthened by its large sample size and adjustments for confounders. Potential limitations include a short follow-up period that cannot rule out reverse causality and the reliance on self-report for confounding factors. The authors' decision not to provide the details of their research in order to reproduce results or replicate procedures is confusing; However, the non-controversial nature of the results makes a detailed examination of their research methods less necessary.