Regular aerobic exercise, popularly generally known as “cardio,” is linked to a significantly lower risk of death from flu or pneumonia, even at weekly levels below those beneficial, finds US research published online within the British Journal of Sports Medicine.

Study: Leisure-time physical activity and mortality from influenza and pneumonia: a cohort study of 577,909 US adults. Image Credit: BGStock72 / Shutterstock

However the findings suggest that there could also be a level above which the consequences plateau or turn into potentially harmful within the case of muscle-strengthening activities. 

Adults are advised to clock up no less than 150 minutes/week of moderate intensity, or 75 minutes of vigorous intensity, aerobic physical activity, or an equivalent combination, plus muscle-strengthening activity of moderate or greater intensity no less than twice per week.

Aerobic exercise, which incorporates brisk/speed walking, swimming, running, and stair climbing, is sustained, increasing heart rate and dealing up a sweat. Muscle strengthening activities include using weights and resistance bands; exercises comparable to squats, lunges, and press-ups (calisthenics); and heavy gardening.

In addition to helping to take care of good health and ward off serious illness, regular physical activity might also protect against death from flu or pneumonia, the evidence indicates.

The researchers, subsequently, wanted to seek out out if specific types and amounts of physical activity may be related to this reduced risk.

They drew on the responses of 577,909 adults who participated within the US nationally representative National Health Interview Survey (NHIS) between 1998 and 2018. 

Respondents were asked how often they spent 10 or more minutes in vigorous intensity and lightweight or moderate intensity aerobic activities. They usually were asked how often they did muscle-strengthening activities. 

Every person was then categorized based on how well they met beneficial aerobic activity + muscle strengthening weekly targets: not meeting either; meeting the aerobic activity goal, meeting the muscle-strengthening goal, and meeting each targets.

Five levels of physical activity were defined: below 10, 10–149, 150–300, 301–600, and greater than 600 mins/week of moderate to vigorous physical activity; and lower than 2, 2, 3, 4–6 and seven or more sessions/week of muscle-strengthening activities.

Half the respondents (50.5%) didn’t meet either weekly goal. How well they did so differed significantly based on sociodemographic and lifestyle aspects, underlying health conditions, and whether or not they had been vaccinated against flu and/or pneumonia.

A 3rd (34%) were aerobically inactive, and greater than three-quarters (78%) reported fewer than 2 weekly muscle-strengthening sessions.

During a mean monitoring period of 9 years, 81,431 participants died; 1516 deaths were attributed to flu and pneumonia.

Those that met each beneficial weekly physical activity targets had nearly half (48%) the danger of dying from flu or pneumonia as their peers who met neither, after accounting for potentially influential aspects. 

Meeting only the aerobic activity goal was related to a 36% lower risk after accounting for potentially influential aspects, while meeting only the muscle-strengthening goal wasn’t related to any significant difference in risk.

By way of quantity, clocking up 10–149, 150–300, and 301–600 mins/week of aerobic physical activity was related to, respectively, 21%, 41%, and 50% lower risks, compared with none. But no additional profit was seen above 600 weekly minutes. 

“Although [10-150 mins/week] is commonly labelled ‘insufficient’ since it falls below the beneficial duration, it might confer health advantages relative to physical inactivity,” suggest the researchers.

When it got here to muscle-strengthening activities, compared with fewer than 2 weekly sessions, meeting the weekly goal of two was related to a 47% lower risk, but 7 or more sessions were related to a 41% higher risk.

“While beyond the scope of this study, plausible explanations [for this dichotomy] range from inaccurate responses (comparable to reporting occupational physical activity, which can not confer the identical protective effect as leisure-time physical activity) to haemodynamic ramifications of frequent, high-intensity [muscle strengthening activity],” explain the researchers.

That is an observational study, and as such, cannot establish cause, added to which the researchers acknowledge various limitations. For instance, the study relied on personal recall. At one time limit, the NHIS survey captured only leisure time physical activity in bouts of 10 or more minutes, nor did it distinguish between light and moderate intensity activities.

Nevertheless, the researchers conclude: “Efforts to cut back influenza and pneumonia mortality amongst adults might concentrate on decreasing the prevalence of aerobic inactivity and increasing the prevalence of achieving 2 episodes/week of muscle-strengthening activity.”