Integrating regular bouts of exercise into our busy schedules can sometimes be a tall order, but luckily science is starting demonstrate how short and sharp bursts can produce a surprising range of health benefits, too. A new study has added to this understanding of how high-intensity interval training can improve and help maintain good health, even in sessions lasting only 20 minutes.
High intensity interval training (HIIT), where short, vigorous bursts of exercise are interspersed with recovery periods, is gaining in popularity on the back of its ability to burn fat, but lately we're learning how it can offer much more. This has included studies demonstrating how it can improve brain plasticity and others that reveal striking effects on metabolic health. We've also learned how performing these sessions in the cold could help boost fat metabolism.
This new study focuses specifically on low-volume (HIIT), where the total time of the sessions including warm up and cool down last no longer than around 20 minutes, with less than 15 minutes of actual high-intensity exercise. The collaborating authors in Canada and Australia reviewed a decade's worth of existing literature on the subject, which yielded some interesting findings.
Currently, the World Health Organization (WHO) recommends adults perform between 150 and 300 minutes of moderate exercise, or 75 to 100 minutes of vigorous exercise per week. The authors found that low-volume HIIT exercise confers comparable, or even at times superior, improvements in metabolic health, heart function and arterial health, despite taking far less time and energy.
Further work is needed to understand the physiological reasons for this, but the scientists say the metabolic improvements appear to be caused by enhanced mitochondrial function and insulin sensitivity. Some cardiovascular improvements, meanwhile, appear to be associated with increased left ventricular function and greater central and peripheral arterial compliance.
These findings provide useful information not just for time-poor folks with little time to exercise, but people with health issues and a compromised capacity for physical activity. This was demonstrated through an earlier study published by the same research team, where four-minute sessions of HIIT, three times per week, were found to improve blood-sugar levels, liver fat and cardiorespiratory fitness in type 2 diabetics.
“While the WHO guidelines may serve their purpose at a populational level, individualized and tailored low-volume HIIT interventions delivered by appropriately trained exercise professionals may be more effective at an individual level, especially for time-poor individuals," says study author Dr. Angelo Sabag. "This research is especially important now as people are looking for new and exciting ways to engage in regular exercise, after a year of lower physical activity due to the pandemic.”
The research was published in the Journal of Physiology.
Source: The Physiological Society