In a recent article published in Nature Medicine, researchers investigated the health-enhancing effects of vigorous intermittent lifestyle physical activity (VILPA) if incorporated into the daily lives of non-exercisers unable to indulge in vigorous physical activity (VPA).
Background
Previous guidelines did not acknowledge that physical activity bouts lasting less than 10 minutes provided health benefits. They often propagated that leisure activities, such as gymming, running, and sports, provide health benefits. However, VPA has remained cumbersome, especially for middle-aged adults ≥ 40 years, owing to time constraints and the commitment it needs. Also, it requires access to facilities and specific preparation.
On the contrary, VILPA, which refers to sporadic bouts of one to two minutes of VPA (e.g., fast walking, stair climbing), could be incorporated into everyday life. It likely elicits the same effects in physically inactive adults who do not exercise as VPA in exercisers. Thus, the new emphasis is on all physical activities regardless of bout duration.
Regardless of the domain, physical activity reduces the risk of all-cause mortality, plus mortality due to cardiovascular diseases (CVD) and specific cancers. Thus, there is an urgent need for studies examining the associations of VILPA with all-cause mortality, including CVDs and cancers in non-exercisers. Wearable devices (e.g., accelerometers) could capture ‘micro-patterns’ of VILPA, which could help better understand its effect on non-exercisers health.
About the study
In the present study, researchers recruited 25,241 non-exercisers from the United Kingdom (UK) biobank with accelerometry data to examine the correlation between VILPA and all-cause, CVD, and cancer-mortalities. An analysis of 2,407 participants from the core sample set of 25,241 confirmed that the non-exercisers were stable over time. These individuals did not indulge in leisure-time exercise(s) or more than one recreational walk per week 5.5 years before or 1.5 years before the accelerometry baseline.
The study analysis covered two bouts of all VILPA, with 92.3% and 97.7% of bout lengths being up to one and two minutes, respectively. The daily average and maximum VILPA daily timespan were four and 16 minutes per day for both these bout lengths. The researchers estimated the relationship of all-cause mortality with VILPA using a multivariable-adjusted analyses model. They presented the hazard ratio (HR) associated with the lowest dose inducing 50% of the total effect(s) and 95% confidence intervals (CIs). Additionally, they reported the average and maximum VILPA timespan and frequency for both bout lengths for each day.
Study findings
The study cohort comprised 25241 individuals, of whom 14,178 were women, and the remaining 11,063 were men; all had an average age of 61.8 years. The average follow-up duration of the study was 6.9 years. The researchers noted that engaging in more VILPA for about four to five minutes per day led to more mortality risk reductions across all three outcomes assessed in the study in a non-linear fashion.
Previous proof-of-concept trials have shown, and this study also demonstrated that small doses of exercise-based intermittent VPA equating roughly to engaging in average VILPA of 4.4 minutes daily substantially improved cardiorespiratory fitness and reduced CVD mortality risk by 32 to 34%. Moreover, higher cardiorespiratory fitness of 3.5 ml of oxygen uptake per kilogram per minute could lead to a 7% reduction in cancer mortality risk. Fewer than two VILPA bouts of one to two minutes reduced cancer and all-cause mortality by 24% to 26%.
A recent US study reported similar results and showed that less than 31 minutes of VPA per week reduced CVD mortality risk by 36% to 45%. Despite comparable effect size, it was a questionnaire-based study that could capture sequential times in which individuals performed vigorous physical activity with interruptions and rest rather than the actual time of VPA that accelerometers used in this study could quantify.
To summarize, nearly three to four minutes of VILPA per day substantially lowered all-cause, CVD, and cancer mortality risk, with steeper reductions towards the lower end of the VILPA distribution.
Conclusions
The current study results were encouraging for those who engage in higher-intensity physical activity, such as VILPA, yet are unaware that this has health benefits. Individuals who find structured exercise infeasible may consider VILPA, for it is a time-efficient and potentially effective intervention. It could accrue health benefits for non-exercisers, just as VPA does for formal exercisers, especially against CVDs and specific cancers. Thus, the researchers emphasized the need to promote VILPA, besides leisure time exercises, through public health and clinical guidelines.
