Increasing exercise intensity offers additional health benefits

Although most health benefits associated with meeting recommended weekly exercise goals can be achieved through moderate physical activity, increasing vigorous physical activity can come with added health benefits, researchers said.

The 2018 Physical Activity Guidelines for Americans recommend that adults participate in at least 150 to 300 minutes weekly of moderate intensity physical activity (MPA), 75 to 150 minutes weekly of vigorous physical activity (VPA) or an equivalent combination of both types of physical activity.

Yafeng Wang, MSc, of the department of epidemiology and biostatistics in the School of Health Sciences at Wuhan University in China, and colleagues examined whether increased VPA — as a proportion of total moderate to vigorous physical activity (MVPA) — would lead to additional reductions in mortality among 403,681 adults (mean age, 42.8 years; 51.7% women; median years of follow-up, 10.1 years).

In mutually adjusted models considering the recommendations of moderate physical activity (MPA), the researchers found that regardless of exercise intensity there were similar associations all-cause mortality (HR for MPA = 0.83; 95% CI, 0.80-0.87 vs. HR for VPA = 0.8; 95% CI, 0.76-0.84) and CVD mortality (HR for MPA = 0.75; 95% CI, 0.68-0.83 vs. HR for VPA = 0.79; 95% CI, 0.70-0.91). However, VPA (HR = 0.89; 95% CI, 0.80-0.99) showed a stronger inverse association with cancer mortality vs. MPA (HR = 0.94; 95% CI, 0.86-1.02). Among adults who engaged in any MVPA, a higher proportion of VPA to total physical activity was associated with lower all-cause mortality but not lower mortality due to CVD and cancer. For example, compared with adults with no vigorous activity, those who engaged in greater than 50% to 75% of VPA to total physical activity had 17% lower all-cause mortality (HR = 0.83; 95% CI, 0.78-0.88), independent of total MVPA.

According to the researchers, the link between increased VPA and all-cause mortality was consistent across chronic conditions, lifestyle risk factors and sociodemographic characteristics at baseline. However, the researchers said they “cannot totally rule out the possibility of reverse causality.”

“The main message should be about reaching the minimal amount of 150 minutes per week of MVPA, as most of the benefits could be obtained at MPA,” Wang and colleagues wrote. “Although MPA may be more palatable and applied to most of the population, clinicians and public health interventions may advise that increasing the relative proportion of VPA to total physical activity may be associated with additional health benefits.”