Low Cardiorespiratory Fitness May be Warning Sign for Heart Problems, Even in Healthy People
Cardiorespiratory fitness is the ability of the blood circulation and respiratory systems to deliver enough oxygen to muscles during exercise. It’s measured in VO2max, which is the maximum rate of oxygen consumption during exercise that increases with intensity. A recent study suggests that low cardiorespiratory fitness may be a warning sign for future health problems, even in people who are fit and healthy with no signs of heart or blood vessel disease.
Participants in the study included 4,527 fit and healthy people who had no history of cardiovascular or lung disease, cancer, or high blood pressure. All of the participants were given a face mask and heart rate monitor. They then warmed up on a treadmill for 10 minutes, after which they ran increasingly faster. The researchers measured their oxygen intake to establish their VO2max. They also collected information on tobacco use, alcohol consumption, family history of cardiovascular disease, physical activity, weight, height and waist circumference, blood pressure and cholesterol levels.
The researchers tracked cardiovascular disease for an average nine years of follow-up. During that time, 147 participants (3.3%) were diagnosed with heart disease, died from heart disease, or required an intervention to unblock clogged arteries. When the researchers examined the data, they found a “strong link” between better cardiorespiratory fitness and a reduced risk of a coronary event. The participants in the highest 25% of cardiorespiratory fitness had a 48% lower risk of a cardiovascular event compared to those in the lowest 25%.
The researchers also found that for every extra unit of measurement of cardiorespiratory fitness, the risk of cardiovascular disease fell by 15%. According to the researchers, this shows that greater cardiorespiratory fitness protects against both chronic and acute heart and blood vessel problems.
Researchers from Norwegian University of Science and Technology led the study. It was published on November 29, 2018, in European Heart Journal.