A magic number for heart health
29 June 2011
Imagine being able to calculate one number that would tell you just how fit you are – and what that means for your heart health. Researchers from the Norwegian University of Science and Technology (NTNU) has managed exactly that: they have developed a model that can help doctors – and individuals – determine just how fit an individual is, and what that means for overall health.
Scientists at NTNU's newly established KG Jebsen Centre of Exercise and Medicine, led by Professor Ulrik Wisl°ff, have assembled the largest dataset of its kind in the world on fitness in healthy women and men. Using the database, the researchers were able to develop a model that enables the calculation of maximum oxygen uptake (VO2max), which is the single best way to measure physical conditioning and cardiac health.
5000 Norwegians provide data
Until now, there has been relatively little information to describe the levels of fitness that could be expected in a healthy adult population. That led Wisl°ff and his colleagues at the Jebsen Centre to look at how fitness is related to traditional risk factors, by testing approximately 5000 healthy Norwegians aged 13-90 years.
The researchers found that women's and men's fitness (oxygen uptake) was 35mL / kg / min and 45mL / kg / min, respectively. This figure dropped by about 5% for each decade of increasing age for both sexes. For example, women in their 20s had a VO2max on average of 45mL / kg / min, by the time a woman reaches her 50s, that number was closer to 34mL / kg / min.
Women and men who had lower fitness (regardless of age) than the average for their gender were respectively 5 and 8 times more likely to have many risk factors for cardiovascular disease compared with those who had fitness values higher than average.
Conditioning a continuous measure of health status
The researchers also found that conditioning seems to reflect a continuous measure of health status, and that just a 5mL / kg / min decrease in oxygen consumption was associated with an approximately 60% higher chance of having a collection of several risk factors for cardiovascular disease. The study confirms that a person's physical condition is even more important for heart health than previously thought.