A daily brisk walk for 11 minutes or more can lower the risk of early death, according to a new study published in the British Journal of Sports Medicine. Any moderate-intensity physical activity performed for 11 minutes every day, or 75 minutes of activity a week, would be sufficient to lower the risk of diseases such as heart disease, stroke and a number of cancers, the study, led by researchers from University of Cambridge, said. 


What are moderate-intensity physical activities?


Moderate-intensity physical activities increase one's heart rate and make them breathe faster. These activities can be performed easily, and one will still be able to speak while performing it. Examples of moderate intensity physical activity include brisk walking, riding a bike, hiking, dancing and playing tennis or badminton. 


Cardiovascular diseases such as heart disease and stroke were responsible for 17.9 million deaths in 2019. These diseases are the leading cause of death. In 2017, cancers were responsible for 9.6 million deaths, the study said. 


Moderate-intensity physical activity is known to reduce the risk of cardiovascular disease and cancer. The United Kingdom's National Health Service (NHS) recommends that adults perform at least 150 minutes of moderate-intensity activity or 75 minutes of vigorous-intensity activity each week, the study stated. 


According to the researchers, if everyone managed at least half the recommended level of physical activity, one in ten early deaths could be prevented.


How the study was conducted


Researchers from the University of Cambridge conducted a systematic review and meta-analysis after pooling and analysing cohort data from all published evidence, in order to explore the amount of physical activity necessary to have a beneficial impact on several chronic diseases and premature death. Using this approach, they brought together studies that on their own did not provide sufficient evidence. 


The researchers looked at the results reported in 196 peer-reviewed articles, which covered more than 30 million participants from 94 large study cohorts. Using the data, the researchers prepared the largest analysis to date of the association between physical activity levels and risk of heart disease, cancer and early death. 


Outside of work-related physical activity, two out of three people reported activity levels below 150 minutes per week of moderate-intensity activity, the study found. Fewer than one in ten people managed more than 300 minutes of moderate-intensity physical activity per week. 


Why it is important to perform at least 75 minutes of of physical activity per week


The researchers found that the additional benefits in terms of reduced risk of disease or early death, when one performed more than 150 minutes per week of moderate-intensity physical activity, were marginal. However, even half this amount came with significant benefits, the study said. 


A total of 75 minutes of moderate-intensity physical activity per week brought with it a 23 per cent lower risk of early death. 


In a statement released by the University of Cambridge, Dr Soren Brage, one of the authors on the paper, said if a person finds the idea of 150 minutes of moderate-intensity physical activity a week a bit daunting, then the findings of the study should be good news for them. This is because doing some physical activity is better than doing none. 


Brage said this is also a good starting position because if one finds that 75 minutes a week is manageable, then they could try stepping it up gradually to the full recommended amount. 


The study found that 75 minutes per week of moderate-intensity physical activity was also enough to reduce the risk of developing cardiovascular disease by 17 per cent and cancer by seven per cent. The reduction in risk was greater for specific cancers, such as head and neck cancers, gastric and cardiac cancers, myeloid leukaemia and myeloma. The reduction in risk for these was 14 to 26 per cent.


A three to 11 per cent lower risk was observed for other cancers such as lung, endometrial, breasts, colon and liver cancer.


What benefits does 150 minutes of physical activity per week provide?


If everyone in the studies had done the equivalent of at least 150 minutes per week of moderate-intensity physical activity, around one in six, or 16 per cent early deaths would have been prevented, the researchers calculated. About 11 per cent, or one in nine cases of cardiovascular disease and five per cent or one in 20 cases of cancer would be prevented. 


According to the study, even if everyone managed at least 75 minutes per week of moderate-intensity physical activity, one in twenty, or five per cent cases of cardiovascular disease, and nearly one in thirty, or three per cent cases of cancer would be prevented. 


Walking, cycling to work instead of using the car, and engaging in active play are excellent methods of becoming more active.