Short bursts of vigorous activity may lower cardiovascular risk in women

BMJ GroupDec 3 2024

Short bursts of incidental vigorous physical exertion, lasting less than a minute each, may almost halve the risk of a major cardiovascular event, such as heart attack or heart failure among women who don't exercise regularly, finds research published online in the British Journal of Sports Medicine.

Just 1.5-4 daily minutes of high intensity routine activities, such as brisk stair climbing or carrying heavy shopping, may help to stave off cardiovascular disease among those either unwilling or unable to take part in structured exercise or sport, conclude the international team of researchers.

Longer bouts of high intensity physical activity in middle age are associated with significantly lower risks of cardiovascular disease, but it's not clear if much shorter bursts of this level of activity that are often part of a daily routine-;formally known as vigorous intermittent lifestyle physical activity, or VILPA for short-;may also be effective at lowering risk, and if so, what the minimum threshold for measurable effects might be, they add. 

This is particularly important for women who don't or can't exercise regularly, for whatever reason, because women tend to have a lower level of cardiorespiratory fitness than men at any given age, explain the researchers.

To explore this further, they drew on 81,052 middle-aged men and women (average age 61) from the UK Biobank who wore an activity tracker for a full week for 24 hours/day between 2013 and 2015.

Participants were divided into those who reported not doing any regular structured exercise or only going for a recreational walk once a week (22,368) and those who said they were regular exercisers or who went for a walk more than once a week (58,684).

Participants' cardiovascular health was tracked until the end of November 2022, and details of hospital admissions or deaths from heart attack, stroke, and heart failure, collectively known as a major adverse cardiovascular event, or MACE for short, were collated.

Of the non-exercisers,13,018 women and 9350 men with complete data (22,368 in total) were included in the final analysis. And during a monitoring period of nearly 8 years, 331 women and 488 men had a heart attack or stroke, developed heart failure, and/or died of cardiovascular disease.

Specifically, these comprised 379 separate heart attacks (129 women and 250 men); 215 cases of heart failure (96 women and 119 men); and 225 strokes (106 women and 119 men).

After accounting for potentially influential risk factors, such as lifestyle, cardiovascular risk factors, co-existing conditions, and ethnicity, a clear dose–response association emerged for all MACE and separately for heart attack and heart failure in women who said they didn't do any structured exercise but incorporated VILPA into their daily routine.

The associations were less clear and less significant, however, in men. 

For example, women who clocked up a daily average of only 3.4 minutes of VILPA, but no formal exercise, were 45% less likely to have any type of MACE, 51% less likely to have a heart attack, and 67% less likely to develop heart failure than women who didn't manage to include any VILPA .

Men who averaged 5.6 minutes of VILPA/day, but no formal exercise, were 16% less likely to have any type of MACE than men who didn't record any VILPA. But there were no clear associations with the separate components of MACE.

Even smaller amounts of daily VILPA still showed measurable associations with lower cardiovascular risks for women: a minimum of 1.2-1.6 minutes a day was associated with a 30% lower risk of all MACE, and specifically, a 33% lower risk of heart attack, and a 40% lower risk of heart failure.

A minimum length of 2.3 minutes/day of VILPA for men, however, corresponded to only a 11% reduced risk of all MACE.

Among the regular exercisers, no such major sex differences were observed in the dose–response associations between vigorous physical activity and the overall risk of MACE, or heart attack and heart failure. There was evidence of a dose–response association with stroke, but only in men.

This is an observational study and therefore can't establish cause and effect, and an average of 5.5 years elapsed between the activity tracker recordings and collection of data on potentially influential risk factors and leisure time physical activity measurement.

Nevertheless, the researchers conclude: "VILPA may be a promising physical activity target for major cardiovascular events prevention in women unable or not willing to engage in formal exercise."

And although the VILPA findings were strongest for women who didn't exercise, men who incorporate some VILPA into their daily routines should still engage in regular vigorous intensity structured exercise to lower their cardiovascular disease risk, they point out.