Research shows that exercising in intense 30-second bursts can provide more health benefits than 90 minutes of moderate exercise.
Adults are currently advised to do at least 150 minutes of moderate to vigorous activity every week – the equivalent of two and a half hours of running or cycling.
But researchers in the US now say that a short, intense burst of exercise could be a better way to reduce the risk of a range of health problems – including heart disease and cardiovascular disease. diabetes.
“What’s exciting here is that just a few minutes of intense exercise can induce a significant molecular response,” says the study’s lead author, Dr. Paul Cohen.
‘And we’re still seeing it after eight weeks of training, which tells us that this response is not simply a product of the body struggling to keep up with unknown stress.
‘It may be that the reactions we observed are inherent to intensive exercise.’
The research team, based at Rockefeller University in New York, says the findings show that a short period of exercise, which can easily be incorporated into a busy life, can make a big difference if done often enough.
The study – published in the journal Cell Reports Medicine – compared the health benefits of exercising at different intensity levels.
A few minutes of intense exercise can have a greater impact than 90 minutes of moderate exercise
Doing six full sprints of 30 seconds on an exercise bike – with four minutes of rest in between – had the most beneficial effect on the body, they discovered.
In total, just three minutes of intense exercise, performed over a half-hour period, the routine produced rapid changes in 714 blood proteins linked to health and disease.
Proteins in the blood are responsible for transporting essential nutrients and hormones throughout the body, keeping fluid in the blood vessels and fighting infections.
Intense exercise can impact these proteins by placing extreme demands on the muscles – including the heart – forcing them to communicate quickly with the rest of the body.
In response, cells in the body release a wave of signaling molecules into the bloodstream that help regulate energy expenditure and tissue repair.
Compared to sprint cycling, moderate cycling only changed seven proteins.
The team also compared the effects of running for two hours at a moderate pace on the treadmill and found that although this changed more proteins than cycling alone, it was still less effective than sprint cycling.
Sprint cycling also caused an immediate increase in proteins responsible for blood vessel function, tissue repair and hormone signaling.
These short bursts of intense exercise were found to increase levels of Lac-Phe – an exercise-induced molecule previously linked to appetite suppression.
The researchers also found that blood collected after sprint cycling showed signs of major changes in human fat cells – affecting the way they burn energy, respond to hormones and detect nutrients.
Lab tests showed that blood taken after sprint cycling turned on or off more than 1,600 genes in human fat cells, compared to just 25 after moderate exercise.
When the researchers compared these protein levels with health data from more than 53,000 people from the UK Biobank, they found that many of these proteins were associated with a lower risk of heart disease.
The link was particularly striking in obesity and type 2 diabetes – metabolic disorders that affect how efficiently the body produces and uses energy.
Experts think this is because short bursts of intense exercise force the body to quickly switch between fuel sources, strengthening the mechanisms involved in blood sugar control and fat metabolism.
Of the 33 proteins associated with a lower risk of these conditions, 32 were changed by sprinting, compared to just three by moderate exercise.
More than a quarter of these proteins were also linked to slower biological aging.
The researchers said the findings may help explain why high-intensity interval exercises, despite requiring only a fraction of the time of traditional endurance exercises, repeatedly produce powerful health benefits.
“It is well appreciated that different exercise intensities stimulate different body-wide adaptations,” says Luke Olsen, an expert in cell biology and co-author of the study.
‘However, the molecular mechanism linking these intensity-dependent adjustments has remained largely elusive.
‘Our work suggests that exerkines proteins and metabolites released into the bloodstream after exercise are highly sensitive to exercise intensity and may be the key mediators of the health-promoting effects of short bursts of vigorous exercise.’
However, they acknowledge that more work is needed to determine whether the findings are more broadly applicable across different age groups and women.
More than 20 million adults in Britain currently do not meet government guidelines for physical activity.
Around 12 million Brits are considered seriously inactive, getting less than 30 minutes of exercise a week.
