A recent study published in the European Heart Journal shows that even healthy people who don’t show signs of cardiovascular disease, and have low cardio-respiratory fitness may still fall victim to cardiovascular issues in the future. Cardio-respiratory fitness refers to the body’s circulatory and respiratory systems’ ability to transport sufficient oxygen to the muscles during a period of continuous exercise.
The study used data from a population-based study in Norway (the HUNT3 study) that assessed the cardio-respiratory fitness (CRF) of healthy 4,527 adult male and female participants with no history cardiovascular or lung disease, cancer or high blood pressure between 2006 and 2008.
The participants’ CRF levels were measured their VO2max levels – the maximum uptake of oxygen during physical activity. This measurement goes up as the intensity of the exercise increases. To get these readings, the participants wore a face mask and a heart rate monitor while exercising on a treadmill. After a ten-minute warm-up period, the intensity of the exercise kept increasing and their oxygen uptake was measured.
The study’s researchers also assessed the patients’ weight, height, activity levels, waist circumference, blood pressure and cholesterol readings as well as their family history of cardiovascular disease.
After following up with the participants for an average of nine years, the researchers found that the participants with higher CRF had the lowest risk of developing cardiovascular problems. It was also found that overall, just 147 participants from the entire cohort suffered negative cardiovascular events such as heart disease diagnoses and deaths, or needing intervention for blocked arteries.
According to Dr Bjarne Nes, a researcher at the Norwegian University of Science and Technology (NTNU), the cardiovascular disease risk for participants is in the top 25% in terms of highest CRF levels was slashed by almost half when compared that of those in the bottom 25%.
In fact, the risk of cardiovascular disease decreased by 15% for every extra metabolic equivalent (MET). METs are the units used to measure CRF. For instance, people tend to use only one MET when sitting quietly, but use around eight for a high-intensity activity like running.
The study is the first of its kind to have a reliable method to asses the effects of exercise on a healthy cohort by measuring their peak oxygen uptake (VO2peak) during activity.
But the researchers also note that this study’s findings may not apply to the general population. This is because the participants in the study were young, healthy volunteers who may have been attracted to the idea of taking part in exercise-related research. As a result, they were more likely to take steps to stave off the risk of cardiovascular disease, which was already a low one in their case. These factors explain why only around 3.3 per cent of the participants went on to suffer a cardiovascular event.
The take-home message
Despite the study’s limitations, the researchers are positive about their theory: Everyone should try to at least the minimum amount of exercise to meet the minimal requirements drawn out by the European guidelines for disease prevention. They also say that the protective effects that exercise has on the heart only appear to increase as the METs increase – even beyond 12 METs – with no clear upper-limit. But all is not lost if you are unable to exercise for long, as there is also a lot of evidence to suggest that people who have difficulty exercising due to illness or lack of ability are better off doing even a little bit of exercise than none at all.
Source: sciencedaily.com | By Tesneem Ayoub