Scientific Support for Physical Activity

It’s well established that being in pristine physical condition correlates positively with good health. What tends to occur is there is a large subset of the population that’s extremely active and “fit,” while the rest are relatively inactive. I’m a large proponent of focusing on the relatively inactive group and increasing their activity levels as the health benefits with be extreme.
The issue with the inactive cohort is that they experience numerous barriers that have caused them to behave the way they do. A few of the common reasons given are:

    • Time constraints
    • Work schedule
    • Family commitments
    • Lack of belief in physical activity
    • Other conditions (e.g. pain)
    • Content with their health

Another major contributor in the inactivity epidemic is the focus on physical activity and exercise as a means to an end of physical aesthetics. The old adage is that single men and women invest into themselves through exercise in order to attract a mate, and then give it up once they are settled down. Although a generalisation, it’s safe to say that exercise is commonly (and unfortunately) paired with physical attraction . However, not everyone is motivated by wanting to improve the way they appear, especially as careers and family life take over. In order to reduce the world’s tendency to be inactive we need to find tangible factors that give credence to get us moving.   We are also at a crossroads as a generation where technology and the environment around us are continually contributing to populations being inactive. Our ancestors had to walk more as there were no cars. They had to work harder as there were fewer machines. They avoided sitting all day as there was no TV or computer to keep them glued to a chair. It’s therefore imperative that our generation takes an active approach in order to prevent the detrimental affects of inactivity.

Physical Activity vs Physical Fitness

In this article, I want to emphasise that I’m not discussing achieving an elite level of fitness. Physical activity is merely the simplest form of exercise, in that its aiming at getting the body moving. The aim is to show how some physical activity is crucial for those who are relatively inactive due to work, family and time constraints. Get moving.

[learn_more caption=”An Anecdote”] Here’s a story of a 57 year old man who had been a heavy smoker since he was 17 years old. He was married, with kids and had a successful 9-5 career. He was diabetic and partook in minimal physical activity. Work all day, recover all evening type-of-thing. His health did not seem like an issue, he was managing okay day to day and had a few feeble attempts to quit smoking but nothing eventuated. One day, his behaviour caught up with him and he suffered a mild heart attack. Thankfully, that was enough of a scare to quit smoking altogether from that day on. In the coming months he would suffer further health problems as a result of his many years of inactivity and poor health decisions. The moral of the story is that living each day in inactivity might seem like the easy option in the moment. There might not be any glaring reasons to start moving, but with a little foresight it’ll pay off down the track. Not for physical beauty or winning the company arm wrestling competition, but to give you more ammo to enjoy the things you love.[/learn_more]


The Scientific Evidence

For us to buy into the premise of being active, we need to understand what’s the big issue with being inactive in the first place. Below are 5 out of the many reasons that science has found to support the premise of increasing physical activity.

a) 3 weeks of bed rest = 30 years of ageing

A 1996 follow up of an original “Dallas Bed Rest” study in 1966 found that 3 weeks of bed rest at age 20 was equal to the health and fitness decline over a period of 30 years of ageing in the same subjects. 
The impact of this evidence is radical in nature. It presents one of the strongest arguments against physical inactivity. It’s human nature to not want to age too quickly. Remaining physically inactive for a prolonged period of time increases the ageing process dramatically.

Results comparing bedrest to ageing

Results comparing bed rest to ageing

b) Increased physical activity reduces the risk of Cardiovascular Disease

A study by Manson et al in 2002 compared the many different subgroups of populations and examined their relative risk of cardiovascular disease with various ranges of weekly physical activity. They found that regardless of age, body composition, gender and race; increasing weekly physical activity clearly results in a reduced risk of disease.

Physical Activity

In the graphs presented, the energy expended from left to right represents least physical activity to most physical activity. Its important to know that the health benefits of remaining physically active over the long term are evident regardless of what group of people were tested.

[button type=”big”] Increased physical activity reduces cardiovascular health risk regardless of age, gender, socio-economic status.[/button]

c) Inactivity correlates with obesity

Studies have found that physical inactivity can result in up to a 44% increased risk of being overweight, and up to 61% increased risk of being obese.

There are numerous studies that find strong links between being physically inactive and increased fat mass. Since being overweight and obese can greatly increase the risks of developing many other health problems, regular physical activity can directly and indirectly prevent other major health issues.

d) Physical activity increases Life Expectancy

In 1986, a study by Paffenbarger et al, examined the life expectancy of nearly 17,000 university students and how regular physical activity was shown to increase their life expectancy by 28% by just expending over 2000kcal on physical activity each week.

With such a large subset of people tested, finding that those who remained moderately active lived longer is an amazing titbit of evidence to encourage us to incorporate increased physical activity.

e) Physical inactivity results in a major economic burden.

Several studies have explored the financial burden of physical inactivity on the healthcare system. One such study based in Canada attributed $5.3 billion to physical inactivity which was 2.6% of the total healthcare costs in the nation. 

Considering the preventable nature of physical inactivity, $5.3 billion is an extreme figure. Despite the costs for individuals being spread out over a long period of time and often being subsidised by medicare initiatives, we can all agree that pretty much any financial expenditure as a result of inactivity is not ideal for the individual budget and the nation’s budget alike.

Taking Action

Now that we’ve made it through the piles of research evidence outlining how obviously beneficial increasing our physical activity can be lets have a look at some practical strategies that can be implemented to help monitor and increase physical activity levels.

a) Constant Feedback

There are many devices that can help track physical activity levels. There are two types that can be beneficial.

    • Pedometer – Measures steps taken per day. Using a spreadsheet or diary you can manually track what days/events result in the most physical activity versus what causes inactivity.

Omron Pedometer on Amazon


    • Calorimeter – A calorimeter monitors caloric expenditure using the latest technology. It is usually worn on the wrist as a watch. The fitbit is one of the highest rated calorimeters, it tracks sleep as well as steps taken as well as total calorie spend


Fitbit Calorimeter on Amazon

b) Active Decisions

Gym Escalator

Making decisions that are based around keeping you physically active should be considered a habit creation process. At first you might need to recruit an extra serving of willpower in order to become conscious of the choices you are making and how they can be improved. Plan your activities in writing and you will be able to identify the prolonged periods of inactivity and strategise on how physical activity can be included in each activity.

c) Habit Creation

The scientific benefits of consistent physical activity are clear as day. It’s now up to you to increase your self awareness and identify regular strategies to promote increased physical activity. It doesn’t need to be much, but if you develop a system then you can ensure that you are taking your best interests to heart. Here are some simple ideas that can be used:

      • Take the stairs
      • Park your car further away from the station/work
      • Walk the dog first thing in the morning or before bed
      • Take 5 minutes each hour at work to do a few exercises at your desk
      • Go for a walk with your spouse a few times per week
      • Set step count goals for each day (e.g >7000 steps per day)
      • Have a home/work based exercise program designed for you


Physical activity does not need to be strenuous exercise. Your body systems rely on some physical exertion in order to perform at their peak for a longer portion of life. In order to ensure the long term benefits of physical activity are reaped for your health, active habits need to be created and completed consistently. Strategise regularly about your daily activity levels and how you can work around increasing your physical activity in a sustainable and enjoyable way.

Get Moving!


McGuire, D K & Levine, B D & Williamson, J W & Snell, P G & Blomqvist, C G & Saltin, B & Mitchell, J H. (2001). A 30-year follow-up of the Dallas Bedrest and Training Study: II. Effect of age on cardiovascular adaptation to exercise training. Circulation, 104. Retreived from http://www.biomedsearch.com/nih/30-year-follow-up-Dallas/11560850.html

McGavock, J., Hastings, J., Snell, P., McGuire, D., Pacini, E., Levine, B., & Mitchell, J. (2009). A forty-year follow-up of the Dallas Bed Rest and Training study: the effect of age on the cardiovascular response to exercise in men.Journals Of Gerontology Series A: Biological Sciences & Medical Sciences64A(2), 293-299. doi:10.1093/gerona/gln025

Manson, J., Greenland, P., LaCroix, A., Stefanick, M., Mouton, C., Oberman, A., & … Siscovick, D. (2002). Walking compared with vigorous exercise for the prevention of cardiovascular events in women. The New England Journal Of Medicine347(10), 716-725.

Paffenbarger, R. S., Hyde, R. T., Wing, A. L., & Hsieh, C. C. (1986). Physical activity, all-cause mortality, and longevity of college alumni. New England Journal Of Medicine314(10), 605-613.

Tremblay, M., & Willms, J. (2003). Is the Canadian childhood obesity epidemic related to physical inactivity?. International Journal Of Obesity And Related Metabolic Disorders: Journal Of The International Association For The Study Of Obesity27(9), 1100-1105.

Katzmarzyk, P., & Janssen, I. (2004). The economic costs associated with physical inactivity and obesity in Canada: an update. Canadian Journal Of Applied Physiology = Revue Canadienne De Physiologie Appliquée29(1), 90-115.

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