麻豆传媒

For adults who can't or don't like to exercise, short periods of vigorous activity as simple as climbing a flight of stairs may be enough to lower their risk of cancer, according to a large cohort study.

Compared with no vigorous intermittent lifestyle physical activity, the median daily duration of periods of vigorous activity up to 1 minute (totaling 4.5 minutes per day) was associated with a 20% reduction in total cancer risk (HR 0.80, 95% CI 0.69-0.92), reported Emmanuel Stamatakis, PhD, of the University of Sydney in Australia, and colleagues.

Moreover, there was also a 31% reduction in the risk of a physical activity (PA)-related cancer -- a composite of cancer sites known to be possibly associated with low physical activity (HR 0.69, 95% CI 0.55-0.86), they noted in .

"Daily VILPA [vigorous intermittent lifestyle physical activity] may be a promising intervention for cancer prevention in populations not able or motivated to exercise in leisure time," Stamatakis and colleagues wrote. "Long-term trials with cancer-related biomarker outcomes and well-designed cohort studies with wearable devices should further explore the potential of VILPA as a cancer prevention intervention for nonexercising individuals and for those who find structured exercise unappealing."

The researchers also found that a "minimal dose" of 3.4 minutes of vigorous activity per day was associated with a 17% reduced risk of total cancer incidence (HR 0.83, 95% CI 0.73-0.93), while 3.7 minutes daily was associated with a 28% reduced risk of physical activity-related cancer incidence (HR 0.72, 95% CI 0.59-0.88).

In an , Linda S. Lindström, MSc, PhD, of Karolinska University Hospital in Stockholm, and colleagues, noted that studies have suggested that physical activity can also improve physical fitness, muscle strength, cancer-related fatigue, and quality of life among cancer survivors, adding that whether the results of this study can be extrapolated to cancer patients needs to be evaluated.

In any event, they said that it is clear that most individuals benefit from physical activity, "and the key is to make exercise a habit."

However, based on the findings of this study, they pointed out that even sporadic episodes of brief, vigorous physical activity can positively affect health and reduce the risk of disease, adding that "any physical activity is better than none."

This analysis included 22,398 adults from the U.K. Biobank accelerometry subsample (mean age 62 years, 54.8% women, 96.0% white). Only individuals who reported no leisure time exercise and one or fewer recreational walks a week were included.

Vigorous intermittent lifestyle physical activity is defined as short periods of vigorous physical activity such as bursts of fast walking or stair climbing. Stamatakis and colleagues said that it should only be measured with wearable trackers, such as the wrist-worn accelerometers used by participants in the .

Participants with cancer, cancer in remission, a cancer event during the first year after accelerometry baseline, or inadequate wear time were excluded.

Analyses were adjusted for age, sex, body mass index, education level, smoking status, alcohol consumption, sleep duration, fruit and vegetable consumption, medications, parental cancer history, prevalent cardiovascular disease, daily durations of light- and moderate-intensity physical activity, and daily duration of longer vigorous exercise bouts.

During a mean follow-up of 6.7 years (149,650 person-years), 2,356 new cancer events were reported (1,084 in physical activity-related cancer sites).

Most (92.3%) vigorous activity occurred in bouts of up to 1 minute; the results related to 1-minute bouts were similar to those for up to 2 minutes, the authors noted.

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