Here is the text of the article, accessible for free: Brief bouts of device-measured intermittent lifestyle physical activity and its association with major adverse cardiovascular events and mortality in people who do not exercise: a prospective cohort study.

This is an interesting article reporting on a study done in UK. Adults were selected who did not engage in exercise during leisure time and who did not walk for leisure more than once a week (here, walking for leisure is juxtaposed to walking for transportation). Adults with pre-existing cardiovascular disease, with a cardiovascular negative an event in the first 2 years of follow-up, with self-rated poor health, and those who were underweight or had a high frailty index score were excluded in an effort to reduce the risk of reverse causality. The selected adults were given an accelerometer device to be worn on their dominant wrist. The data from the wearable devices was analyzed and categorized using machine learning methods. Bouts of activity as part of ADL (activities of daily living) were studied. Activities such as playing with children, washing the dishes, mowing the lawn, walking briskly to catch a bus, cutting wood, etc. were studied. None of them were done with the intention to exercise but rather to complete a task.

The machine learning classification came up with the following durations of bouts of physical activity:

<1 min
1-<3 mins
3-<5 mins
5-<10 mins

Outcomes of interest in post-study monitoring of participants were deaths and MACE which stands for Major Adverse Cardiovascular Events.

The paper authors used the acronym MV-ILPA which stands for moderate-to-vigorous intermittent lifestyle physical activity.

The authors concluded that very short bouts of MV-ILPA (of less than 1 min duration) reduced mortality and MACE only if at least 15% of the bout was spent in vigorous activity (this means at least 10 secs). Otherwise they were not effective. But longer bouts were effective. Even from 1 to 3 mins were effective.

The authors propose promoting short intermittent bouts of non-exercise physical activity of moderate-to-vigorous intensity to improve longevity and cardiovascular health among adults who do not habitually exercise in their leisure time. Some of those adults do not want to exercise and others simply cannot. For some, the barrier to entry into structured exercise is too high.

Here is how bouts of activity reduced all-cause mortality: