According to a recent study published in the
European Heart Journal, doing 15 minutes of intense activity spread out across
two-minute intervals each week is linked to a lower chance of death.
“The results indicate that accumulating
vigorous activity in short bouts across the week can help us live longer,” said
study author Dr. Matthew N. Ahmadi of the University of Sydney, Australia. “Given
that lack of time is the most commonly reported barrier to regular physical
activity, accruing small amounts sporadically during the day may be a
particularly attractive option for busy people.”
A second study, also published today in EHJ,
found that for a given amount of physical activity, increasing the intensity
was associated with a reduced likelihood of cardiovascular disease.2 “Our study
shows that it’s not just the amount of activity, but also the intensity, that
is important for cardiovascular health,” said study author Dr. Paddy C. Dempsey
of the University of Leicester and University of Cambridge, UK, and the Baker
Heart and Diabetes Institute, Melbourne, Australia.
Both studies included adults aged 40 to 69
years from the UK Biobank. Participants wore an activity tracker on their wrist
for seven consecutive days. This is an objective way to measure motion, and
particularly sporadic activity of different intensities during the day.
The first study enrolled 71,893 adults without
cardiovascular disease or cancer. The median age was 62.5 years and 56% were
women. The investigators measured the total amount of weekly vigorous activity
and the frequency of bouts lasting two minutes or less. Participants were
followed for an average of 6.9 years. The investigators analysed the
associations of volume and frequency of vigorous activity with death
(all-cause, cardiovascular disease and cancer) and incidence of cardiovascular
disease and cancer after excluding events occurring in the first year.
The risk of all five adverse outcomes reduced
as the volume and frequency of vigorous activity increased, with benefits seen
even with small amounts. For example, participants with no vigorous activity
had a 4% risk of dying within five years. Risk was halved to 2% with less than
10 minutes of weekly vigorous activity, and fell to 1% with 60 minutes or more.
Compared with just two minutes of vigorous
activity per week, 15 minutes was associated with an 18% lower risk of death
and a 15% lower likelihood of cardiovascular disease, while 12 minutes was
associated with a 17% reduced risk of cancer. Further gains were observed with
greater amounts of vigorous activity. For instance, approximately 53 minutes a
week was associated with a 36% lower risk of death from any cause.
Regarding frequency, accumulating short bouts
(up to two minutes) of vigorous activity on average four times a day was
associated with a 27% lower risk of death. But health benefits were observed at
even lower frequencies: 10 short bouts a week was associated with 16% and 17%
lower risks of cardiovascular disease and cancer, respectively.
The second study included 88,412 adults free
of cardiovascular disease. The average age was 62 years and 58% were women. The
investigators estimated the volume and intensity of physical activity, then
analysed their associations with incident cardiovascular disease (ischaemic
heart disease or cerebrovascular disease). Participants were followed for a
median 6.8 years.
The researchers found that both higher amounts
and greater intensity were associated with lower rates of incident
cardiovascular disease. Increasing the intensity led to greater reductions in
cardiovascular disease for the same volume of exercise. For example, the rate
of cardiovascular disease was 14% lower when moderate-to-vigorous activity
accounted for 20% rather than 10% of activity, the equivalent of converting a
14 minute stroll into a brisk seven minute walk.
Dr. Dempsey said: “Our results suggest that
increasing the total volume of physical activity is not the only way to reduce
the likelihood of developing cardiovascular disease. Raising the intensity was
also particularly important, while increasing both was optimal. This indicates
that boosting the intensity of activities you already do is good for heart
health. For example, picking up the pace on your daily walk to the bus stop or completing
household chores more quickly.”
Dr. Paddy C. Dempsey et al,Vigorous physical
activity, incident heart disease, and cancer: how little is enough?European