Data support value of any and all exercise
The Nature Medicine study supports other recent research showing the value of short, intense bursts of physical activity. A pair of recent studies also used fitness trackers to measure activity in adults and assess the benefits on outcomes including death and heart disease.
One of these studies, which was published in the European Heart Journal, also used fitness trackers to measure physical activity at moderate and vigorous levels. The researchers found that individuals who performed at least 20% of their physical activity at a moderate to high level, such as by doing brisk walking in lieu of strolling had a significantly lower risk of heart disease than those whose daily activity included less than 20% at a moderate or intense level.
In another study from the European Heart Journal, researchers found that short bursts of vigorous physical activity of 2 minutes or less adding up to 15-20 minutes per week was enough to reduce mortality by as much as 40%.
Plus, a meta-analysis published in the Lancet showed a decrease in all-cause mortality with an increase in the number of daily steps, although the impact of stepping rate on mortality was inconsistent.
“Many studies have investigated the health benefits of physical activity, but not the importance of these difficult-to-capture VILPA bouts that accrue during the course of normal activities of daily living,” Lee Stoner, PhD, an exercise physiologist and director of the Cardiometabolic Lab at the University of North Carolina at Chapel Hill, said in an interview.
Dr. Stoner, who was not involved in the Nature Medicine study, said he was not surprised by the overall finding that doing short bursts of activity impacted mortality and cardiovascular disease, but was slightly surprised by the strength of the evidence.
“The referent group in the Nature Medicine study were those accruing no VILPA”, likely meaning they were very inactive,” Dr. Stoner said and added that he thinks this demonstrates the value of VILPA.
Even without immediately meeting the specific numbers recommended by the CDC, “any physical activity is better than none, especially if vigorous, and VILPA can be built into normal daily routines,” Dr. Stoner added.
What’s missing in short bursts?
Short bursts of activity do have their limits when it comes to overall fitness, said Dr. Stoner.
“Endurance will not be improved as much through short bursts, because such activities are unlikely to be as effective at empowering the mitochondria – the batteries keeping our cells running, including skeletal muscle cells,” he said. “Additionally, the vigorous bouts are unlikely to be as effective at improving muscular strength and endurance. For this, it is recommended that we engage each muscle group in strengthening exercises two times per week.”
However, Dr. Stoner agreed that prescribing short bursts of intense activity as part of daily living may be a great way to get people started with exercise.
“The key is to remove barriers to physical activity pursuit, then focusing on long-term routine rather than short-term gain,” he said. “Individuals are better served if they focus on goals other than weight loss, for which physical activity or exercise may not be the solution. Rather, being physically active can improve vigor, make daily activities simpler, and improve cognitive abilities,” and any physical activity is one of the most effective solutions for regulating blood glucose levels and improving cardiovascular risk factors.