When you look at studies that find exercise lowers cancer risk, they’re often framed in terms of which participants were the most active.

Because it’s the most active participants, generally, who enjoyed the most benefit. And that’s good to know.

However, by focusing on the high achievers (more exercise! less cancer!) the more modest benefits enjoyed by less active participants tend to be lost.

Worse, some people will likely throw their hands in the air and see no point in even trying to protect themselves. To them, exercise is daunting. Gyms are expensive. It’s all too complicated.

To these people I say, take heart

There are studies that have found that even a small amount of physical activity significantly cuts the risk of certain cancers.

In July, I reported on a University of Sydney study that found if you pick up the pace while doing ordinary household chores – such as mopping the floor or carrying groceries through the supermarket car park – your risk of certain cancers can drop by nearly a third.

The key is to go all out, vigorously, for at least a minute – to the point where you’re huffing and puffing like an athlete at the finish line.

Don’t panic

The study found that a modest total of 4.5 minutes of this domestic-related vigorous activity is all that’s required to cut those cancer risks by up to 32 per cent. That’s 4.5 minutes a day. Doing your everyday chores. But at a faster rate.

In a previous study by the same researchers, as we reported in December, found that these tiny kitchen-cleaner workouts were “associated with up to 40 per cent reduction in all-cause and cancer-related mortality”.

There was also up to a 49 per cent reduction in death related to cardiovascular disease.

A lot of gain for little pain

Maybe you’ve started making an effort. Riding a bike three times a week. Walking at a good pace when headed to the shops. A regular bout of hit-and-giggle tennis. And of course, picking up the pace when doing the housework.

With a bit of regularity, you’ve established for yourself a home-made cardiorespiratory fitness routine.

A 2019 study has established – in real numbers – that cardio fitness significantly lowers the risk of developing colorectal and lung cancers.

It also found that people who developed these cancers, and were otherwise fit, were less likely to die than people with low fitness levels. See our report here.

Prostate cancer and heart health

Prostate cancer tends to fall through the cracks when we talk about exercise and cancer risks.

The factors associated with a higher risk of developing prostate cancer include:

• Age. The risk of developing prostate cancer increases rapidly from age 50; it is most commonly diagnosed in people aged between 60 and 79.
• Family history.  Those who have a father or brother with prostate cancer who were diagnosed before the age of 60, or who have a family history of breast or ovarian cancer, are more likely to develop prostate cancer.
• Changes in certain genes that can be carried in families. Inherited mutations in certain genes, such as the BRCA1 or BRCA2 genes, may increase the risk of developing prostate cancer in some people.

None of these you can change.

Exercise is a modifiable lifestyle factor that we know protects against type 2 diabetes, obesity and being overweight, heart disease and some cancers.

So what about prostate cancer? It’s tricky, even a little weird.

Being overweight or obese are main risk factors for developing advanced prostate cancer. This means that once you have prostate cancer, you should keep your weight down to help prevent it from advancing to a stage where it will kill you.

But there has been insufficient evidence exists to extend this conclusion to non-advanced prostate cancer. Meaning, it wasn’t certain that losing weight might (but not always) stop you developing prostate cancer in the first place.

A link is found!

Researchers from the Department of Physical Activity and Health, Swedish School of Sport and Health Sciences, Stockholm appear to have cracked the case.

For a new study, they drew on a national occupational health profile assessment database, focusing on 57,652 men. Information on physical activity, lifestyle, perceived health, measurement of body mass and height was collected. Plus, results of at least two cardiorespiratory fitness tests, measured by peddling on a stationary cycle, were recorded.

Annual cardiorespiratory fitness measurements were expressed as absolute and relative V02 max. This is the amount (volume) of oxygen the body uses while exercising as hard as possible.

The participants were divided into groups according to whether these increased annually by more than three per cent, fell by more than three per cent, or remained stable.

The participants were grouped according to whether their cardiorespiratory fitness had increased, remained stable, or had fallen.

Those whose fitness had improved by three per cent or more a year were 35 per cent less likely to develop prostate cancer than those whose fitness had declined.

They didn’t find a link between heart fitness and dying from the disease.

Still, the researchers conclude “that men should be encouraged to improve their level of fitness to help lower their chances of getting the disease”.

See more about the study here.

 Intensity matters

Speaking to The Guardian, the study’s co-author Dr Kate Bolam said the “more intensive activity, the lower the requirement for duration and frequency”.

In other words, if you up the intensity of your exercise, you don’t have to work out as long or as often to get these results.

Dr Bolam also advised that “getting more muscles involved will have greater aerobic challenge on the cardiovascular system”.

The trick, she said, “is to challenge your cardiovascular system on a regular basis so it improves to match the requirements placed on it. It could even be line dancing if that gets your heart rate up and you have fun.”