Every 40 seconds, an individual in the United States suffers a heart attack. Annually, approximately 805,000 people in the US experience a heart attack, of which 605,000 are their first occurrence.

Engaging in physical activity, especially at a moderate-intensity level, is a well-known way to lower the risk of cardiovascular disease and cancer.

The CDC recommends that adults complete at least 150 minutes of moderate-intensity activity or 75 minutes of vigorous-intensity activity per week.

Scientists from the Medical Research Council (MRC) Epidemiology Unit at the University of Cambridge conducted a systematic review and meta-analysis, pooling and analyzing cohort data from all of the published evidence, to investigate the minimum amount of physical activity required to have a beneficial impact on several chronic diseases and premature death.

The findings of the study were published today in the British Journal of Sports Medicine.

They were able to draw more solid findings by combining research that, individually, did not give enough evidence and sometimes contradicted one another.

To conduct the biggest analysis to date of the link between physical activity levels and risk of heart disease, cancer, and early mortality, scientists examined data from 196 peer-reviewed papers comprising more than 30 million people from 94 significant research cohorts.

Less than one in ten adults reported managing more than 300 minutes per week of physical exercise outside of work-related physical activity, and two out of three reported activity levels below that.

Generally speaking, they discovered that the advantages of physical exercise beyond 150 minutes of moderate intensity per week in reducing the risk of illness or premature mortality were marginal.

Yet even only half of this amount had positive effects: 75 minutes per week of moderate-intensity exercise was associated with a 23% decreased risk of premature death.

“If you are someone who finds the idea of 150 minutes of moderate-intensity physical activity a week a bit daunting, then our findings should be good news” remarks Dr Soren Brage from the MRC Epidemiology Unit, adding, “doing some physical activity is better than doing none. This is also a good starting position – if you find that 75 minutes a week is manageable, then you could try stepping it up gradually to the full recommended amount.”

Also, 75 minutes per week of moderate exercise was sufficient to cut the risk of developing cancer and cardiovascular disease by 7% and 17%, respectively.

The chance of developing some cancers, such as those of the head and neck, myeloid leukemia, and myeloma, was reduced by between 14 and 26%. Gastric cardia cancer was also associated with a reduced risk of between 14 and 26%. A 3–11% decreased risk was shown for various malignancies such lung, liver, endometrial, colon, and breast cancer.

“We know that physical activity, such as walking or cycling, is good for you, especially if you feel it raises your heart rate,” adds Professor James Woodcock, “but what we’ve found is there are substantial benefits to heart health and reducing your risk of cancer even if you can only manage 10 minutes every day.”

The researchers figured that about one in six (16%) early deaths could have been avoided if everyone in the studies had done the equivalent of at least 150 minutes per week of moderate-intensity activity. It would prevent 11% of cardiovascular disease cases and 5% of cancer cases.

Nonetheless, even if everyone were to complete at least 75 minutes a week of moderate-intensity exercise, around 10% of early deaths would be avoided. It would prevent around 3% of all cancer cases and 5% of cardiovascular disease instances.

“Moderate activity doesn’t have to involve what we normally think of exercise, such as sports or running,” comments Dr. Leandro Garcia from Queen’s University Belfast. 

“Sometimes, replacing some habits is all that is needed. 

“For example, try to walk or cycle to your work or study place instead of using a car, or engage in active play with your kids or grand kids. Doing activities that you enjoy and that are easy to include in your weekly routine is an excellent way to become more active.”

What kinds of activities count as moderately intense?

Physical activity with a moderate level of intensity raises your heart rate and makes you breathe faster, but you can still talk while doing it. Examples include:

• Brisk walking
• Dancing
• Riding a bike
• Playing tennis
• Hiking.

Source: 10.1136/bjsports-2022-105669

Image Credit: Getty