Study Finds Least Fit Require More Exercise for Equal Cardiovascular Risk Reduction
New research indicates that individuals with the lowest fitness levels must engage in 30 to 50 minutes more exercise weekly than their fittest counterparts to achieve an equivalent decrease in cardiovascular risk.
The study analyzed data from over 17,000 British adults participating in the UK Biobank study. Participants, aged 40 to 69, underwent a cycle test to estimate their baseline cardiorespiratory fitness (VO2 max) and wore fitness trackers for one week to monitor typical physical activity levels.
Over an average follow-up period of eight years, researchers recorded more than 1,200 cardiovascular events, including heart attacks, atrial fibrillation, strokes, and heart failure.
Current guidelines recommend adults perform at least 150 minutes of moderate to vigorous physical activity weekly, such as brisk walking, cycling, or running.
Published in the British Journal of Sports Medicine, the study found that meeting this guideline corresponded with an 8-9% reduction in cardiovascular risk.
“Given that large proportions of the population do not meet even this benchmark, the primary public health message remains straightforward: achieving 150 minutes per week of moderate to vigorous activity delivers meaningful cardiovascular protection regardless of fitness level,” the authors conclude.
The research further quantified that increased exercise levels led to additional risk reduction. However, those with the lowest fitness required approximately 30 to 50 extra minutes of moderate to vigorous physical activity weekly to gain the same cardiovascular benefits as the fittest individuals.
Specifically, to achieve a 20% reduction in cardiovascular risk, the least fit needed about 370 minutes of such activity per week, compared to 340 minutes for the most fit.
For a risk reduction exceeding 30%, the least fit would need to engage in over 10 hours (610 minutes) weekly, while the most fit would require just over nine hours (560 minutes).
“This finding highlights the steeper challenge faced by deconditioned populations,” the research concludes.
“Current moderate-to-vigorous physical activity guidelines provide a universal but modest safety margin, whereas optimal cardiovascular protection may require substantially higher activity volumes.”
“Future guidelines and implementation strategies may need to differentiate between the minimal moderate-to-vigorous physical activity volume required for a basic safety margin and the substantially higher volumes necessary for optimal cardiovascular risk reduction.”
Expert Reactions and Public Health Implications
The findings appear to contrast with earlier research suggesting that 150 minutes of moderate to vigorous physical activity weekly could reduce older adults’ risk of premature death by approximately 25%.
However, some experts have criticized the recommendation of more than nine hours of exercise per week as unrealistic.
Aiden Doherty, professor of biomedical informatics at the University of Oxford, commented:
“We can’t give much weight to the figure of 560-610 minutes of exercise a week.
Clearly there will be cardiovascular benefit for people who are able to do (more than) 1 hour 20 minutes of moderate-to-vigorous intensity physical activity a day but this is not a sensible public health message.
The public should continue to aim for at least 150 minutes of moderate to vigorous intensity of physical activity a week; more is better; every move counts.”
In response to the study, a spokesperson from Sport England emphasized the importance of increasing activity levels to promote long-term health:
“Emerging research like this reinforces the importance of helping more people be active, more often.
Sport England’s own research shows activity relieves healthcare issues for both individuals and the NHS, preventing 1.3 million cases of depression, 600,000 of diabetes and 57,000 of dementia.”
