Many people want to exercise more, but busy schedules often get in the way. Finding several hours each week for fitness can feel impossible when work, family and other responsibilities compete for attention.
New research suggests that people may not need as much exercise as they think to improve their health, as long as the activity is intense enough.
The findings come from researchers at the Norwegian University of Science and Technology (NTNU) and the Cardiac Exercise Research Group (CERG).
Their work draws on more than two decades of research and large population studies. The researchers argue that short bursts of vigorous activity can produce meaningful health benefits and may be easier for many people to fit into daily life.
Current health guidelines recommend at least 150 minutes of moderate exercise each week, with 300 minutes providing even greater benefits. While these recommendations remain important, many adults struggle to reach them.
According to the researchers, around 30 minutes of high-intensity exercise spread across a week may also improve health for many people.
High-intensity exercise means working hard enough to become noticeably out of breath. People using a heart-rate monitor should aim for about 85% of their maximum heart rate. A simple way to judge the effort is the talking test. You should still be able to speak a few words, but holding a long conversation or singing should be difficult.
Professor Ulrik Wisløff explained that lack of time is one of the biggest reasons people avoid exercise. Short, vigorous sessions may remove this barrier. Improving cardiovascular fitness is especially important because it is one of the strongest predictors of future health and has been linked with a lower risk of more than 30 chronic diseases.
Earlier CERG research involving about 60,000 people found that better cardiovascular fitness was associated with a 40% to 50% lower risk of premature death. More recent studies from Norway and other countries have reported similar results. These findings suggest that improving fitness, even by a small amount, may have long-term health benefits.
The researchers recommend spreading exercise across several days instead of doing one long weekly workout. The benefits of vigorous exercise on blood pressure and blood sugar can last for one or two days. Exercising two to four times each week may therefore help maintain these positive effects.
High intensity does not mean everyone has to sprint or perform difficult workouts. The right level depends on personal fitness. For some people, walking quickly uphill is enough to become breathless. Others may choose interval training such as 20-second or 45-second bursts followed by short recovery periods.
The team also introduced a new measurement called the Activity Quotient, or AQ, which focuses on heart-rate intensity instead of counting only steps or exercise time. Their studies suggest that people reaching at least 25 AQ points each week have lower risks of lifestyle-related diseases, while even greater benefits appear at 100 points or more.
The strength of this work lies in its use of many large population studies rather than relying on a single experiment. However, the article mainly summarises previous research instead of reporting one new clinical trial, so individual responses may differ.
The evidence strongly supports staying physically active, but people with heart disease or other medical conditions should seek medical advice before beginning vigorous exercise.
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