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Around the globe, low levels of physical activity are a major risk factor for most common chronic diseases including type 2 diabetes and many kinds of cancer, including breast and colorectal cancers.

What is physical activity?

According to the World Health Organisation, physical activity is any bodily movement produced by skeletal muscles that requires energy expenditure. Types of physical activities can be grouped in many ways, for example:

Incidental activities

  • manual labour at work
  • walking to and from home to school, work, shops, etc…
  • household chores like cleaning and gardening

Sporting and leisure activities

  • swimming
  • bicycle riding
  • tennis
  • hiking or bushwalking
  • going to the gym

Muscle strengthening activities

  • yoga or Pilates
  • resistance-band training
  • squats, push-ups, sit-ups and weight training

How much should we be doing?

In most nations, adults are advised to be physically active most days of the week for a minimum of 30 minutes each day, or 150 minutes each week.
Additionally, many countries also recommend that people do muscle strengthening activities at least 2 times each week.

Finally, some countries recommend people do not sit/be inactive for prolonged periods (e.g., no more than 120 minutes at a time).

How much are we doing?

Unfortunately, recent population surveys indicate that in developed nations like Australia, more than half of the adult population does not meet current physical activity recommendations, and that women are less likely to meet them than men.

Why does it matter?

Not only data from observational studies, but objective measures of physical activity using modern technology such as accelerometers, provides compelling evidence that increasing physical activity reduces the risk of common cancers like breast and colorectal cancer by 49% and 34%, respectively.
On the flip side, sedentary behaviour increases the risk of breast and colorectal cancer by 8% and 25%, respectively.

Finally, in people with existing colorectal cancer, moderate physical activity (i.e., following current physical activity recommendations) increase the odds of survival by 18% and high physical activity (i.e., doing 6 or more hours per week) increases the odds of survival by 36%.


As well as eating a healthy, low GI and GL diet, keep active to reduce your risk of developing colorectal cancer, and improve your chances of survival if you have already developed the condition.

Read more:

  1. Papadimitriou and colleagues. Physical activity and risks of breast and colorectal cancer: a Mendelian randomisation analysis. Nat Commun. 2020
  2. Hermelink and colleagues. Sedentary behavior and cancer-an umbrella review and meta-analysis. Eur J Epidemiol, 2022.
  3. Choy and colleagues. Exercise and colorectal cancer survival: an updated systematic review and meta-analysis. Int J Colorectal Dis. 2022.
Dr Alan Barclay, PhD, is a consultant dietitian and chef with a particular interest in carbohydrates and diabetes. He is author of Reversing Diabetes (Murdoch Books), and co-author of 40 scientific publications, The Good Carbs Cookbook (Murdoch Books), Managing Type 2 Diabetes (Hachette Australia) and The Ultimate Guide to Sugars and Sweeteners (The Experiment Publishing).
Contact: Follow him on Twitter, LinkedIn or check out his website.