The physical activity health paradox

Physical activity is one of the best things an individual can do to improve their health and using this rationale conventional thinking may suggest that having a physically demanding occupation therefore contributes positively to health. It is not unusual for people who work in industries such as the building trades to think that the physical nature of their work means that they’re physically active. However it would seem, ‘work is not a workout’ and the physical activity paradox suggests occupational physical activity doesn’t really improve health and can potentially negatively impact on health. 

How can this be? The physical activity paradox is not well understood, however some of the reasons for its existence are discussed below: 

To improve cardiorespiratory fitness requires performance of physical activity at high intensity levels (60%-80% maximal aerobic capacity) and it would seem that even the most physically active workplaces or jobsites aren’t reaching the levels required to improve cardiorespiratory fitness. 

The intensity levels that workers in manual labour occupations typically work at are around the 30%-35% of maximal aerobic capacity. If you spend extended periods of time at this level it can elevate your resting heart rate for 24 hours and an elevated resting heart rate is a risk factor for cardiovascular disease. Occasionally elevating the heart to these levels for extended periods is perfectly normal, however if this is happening daily in the workplace there is potential for problems. 

There is often insufficient recovery time between work shifts on the jobsite. In many occupations there can be a requirement to be physically active for 7-12 hours a day, 5 days a week with limited opportunities for recovery. The term used in sports medicine to describe fatigue associated with ongoing levels of physical activity without rest is overtraining and it would seem that extended periods of fatigue as a result of overtraining can increase cardiovascular disease risk.  

So what can be done? 

Paradox number two, it would seem to manage some of these factors workers in physically demanding occupations need to undertake occasional workouts that push their physiology in to more uncomfortable territory to challenge the cardiorespiratory system and improve cardiorespiratory fitness. Whilst also engaging with strategies and practices that support recovery from the demands of a physically demanding occupation. 

Warwick Maloney KM

More reading: 
Holtermann, A, Krause, N. and van der Beek, A.J. (2018). Editorial The physical activity paradox: six reasons why occupational physical activity (OPA) does not confer the cardiovascular health benefits that leisure time physical activity does. British Journal of Sports Medicine 52(3), 149-150. https://bjsm.bmj.com/content/bjsports/52/3/149.full.pdf 

Holtermann, A. and Stamatakis, E. (2019). Editorial Do all daily metabolic equivalent task units (METs) bring the same health benefits? British Journal of Sports Medicine, 53(16), 991-992. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6691932/pdf/bjsports-2017-098693.pdf 

Two feet firm

With age the likelihood of a fall occurring increases, it also becomes more likely that a fall will result in a serious injury. As Australia’s population is ageing, there is likely to be an increase in the occurrence of falls and fall related injuries. Falls are the most common cause of injury in older people and can affect their independence, activity levels, social interactions and quality of life. Treatment of fall related injuries is also of great expense to Australian health services. 

Some common risk factors for a falls occurrence include; older age, falls history, poor balance, muscle weakness, impaired vision and taking multiple medications. These risks can be managed via a multifactorial approach that may include exercise interventions, improving vision, reviewing medication and modifying living environment. 

Exercise is a particularly good intervention for preventing falls as it can address multiple risk factors and has been shown to improve muscular strength, balance, balance confidence and walking speed. An exercise program focusing on preventing falls should see the participant undertaking regularly physical activity, incorporating balance challenges totaling at least two hours a week. Good balance exercises may involve controlled body movements while standing with the feet close together (or standing on one leg), with as little arm support as possible. The exercises should be safe, but challenging and should aid in developing postural and lower limb strength. Tai chi has been proven to be an effective form of exercise to aid in the prevention of falls in healthy older people. 

If you think you are at falls risk and requiring guidance speak with your GP. 

More reading: Australia and New Zealand Falls Prevention Society, http://www.anzfallsprevention.org/ 

*Disclaimer, this is a discussion and does not represent an exercise prescription, for exercise or injury advice seek an appropriately trained health professional. 

The workplace injury trap

Thousands of people every year hurt their backs at work. Whether it’s through lifting something, a slip or fall, motor vehicle accident or being involved in a traumatic event. More often than not the back can return to it’s pre-injury state, but in some cases pain can persist for months and even years. A large amount of research into chronic pain reveals there are a lot of factors that contribute to pain. Believe it or not, but being injured at work actually makes it more likely that pain can be more complicated. So too can factors like impaired movement patterns, difficulty with mental health and coping, even the language you use towards your pain. Whilst structural damage has been shown to be a factor in experiencing pain, emotional stressors and worry can contribute substantially. This is why it is important to treat persistent back pain in a way that considers the physical, psychological and social aspects of a persons life.

It is hard for most to consider that something could be painful without any structural damage or minimal structural damage that has been found to not cause pain including bulging discs and sic degeneration. There are numerous other conditions that can cause pain but have no physical damage such as migraines and fibromyalgia but when it comes to back pain, people find this concept hard to grasp. Sometimes structural damage heals but the pain does not go away or it goes away but comes back years later. How is that possible? Well, once a pain signal is created, your brain never forgets it! This means that your brain can switch on that pain signal whenever it wants, but the brain is pretty smart and only signals pain when danger is perceived to be present. The key word here is perceive because sometimes the brain can think we are in danger when we’re really not which can contribute to chronic pain.

So you may be wondering how pain moves from acute to chronic. As pain becomes more chronic, we become more sensitive to it - like a smoke detector working normally and then turning into a smoke detector that gets set off whenever a candle is lit. Pain is a response to danger, whether that be from a something or someone, weather, sitting, moving or a deadline at work. Triggers are things that make us expect pain. When these triggers happen, if pain occurs, that leads us to expect pain to occur and hence it does even if there is no structural damage anymore. This can lead us to become fearful of that trigger which activates more pain pathways in the brain and causes more pain to be produced. If this trigger becomes a stressor, more pain is created in order to stop us completing that activity. This is why some activities that you used to enjoy, can now cause pain.

As mentioned earlier, pain can also be influenced by emotions and mindset which is not at all to say pain is all in the mind, it is very real, but it can be influenced by emotions. A part of the brain called the anterior cingulate cortex (ACC) has the ability to influence changes in pain and is associated with, you guessed it - emotions. Negative thoughts can tell the ACC to dial up the pain signals and positive thoughts can tell it to dial those pain signals down. Other aspects such as what pain means to you and how it impacts on your life also contribute to how pain is created. This is not to say you just think positive thoughts and pain will magically disappear. Chronic pain takes time to become chronic, so it takes time and numerous reinforcement of positive thoughts to remind your mind that you are safe and capable. And you have to be able to believe that there is a reason to be positive.

As well as reinforcement of positive thoughts, it is also important to set trigger goals. A lot of people with chronic back pain cannot return to work and avoid tasks like lifting things off the ground, housework and even leisure activities, which can become quite depressing. These become triggers for a lot of people and it is important to ease back into completing these tasks slowly, to reinforce that your body is safe when doing them. The key thing is to start off with only completing the task for a short time or until slight discomfort is brought on then stop (e.g. vacuuming for 2-5 minutes). Complete this activity on most days and each week progress by 5-10%. By gradually easing into activities, you are less likely to overdo it and feel like you need a week to recover. A lot of the time when we have lower back pain, we change the way we do things to try to avoid the pain but this can lead to impaired movement patterns and cause some muscles and joints to be overloaded. It is important to continue movement with chronic back pain to help correct these impaired patterns and strengthen muscles to help you return to work and the activities you love.

At Kinetic Medicine, we approach all conditions, especially chronic back pain with what’s technically called a ‘biopsychosocial’ approach. Our positive pain program has been developed specifically for our workers compensation clients to assist them in returning to the activities they love such as motorbike riding, football, even dancing. If you have had an injury at work and are sick and tired of being sick and tired, we’re here to help.

Emma Tunbridge

Cardiac Rehab: the most important kind of rehabilitation

You might be surprised to know that, not all that long ago, the key advice given to people who had suffered a heart attack was to avoid anything stressful – bed rest. But the problems was, when people returned to life shortly after their recovery was deemed over, the number who went on to have further heart attacks and to suffer the worst of fates that accompanies that sort of event was high. The development of cardiac rehabilitation has been a key advance in medical care and potentially the most important application of exercise as medicine. It means that those who suffer a cardiac event can have confidence in their recovery.

A range of conditions, not just heart attack, have a need for cardiac rehabilitation. The include:

• Diagnosed Coronary artery disease

• Coronary angioplasty or ‘stenting’

• Coronary artery bypass surgery 

• Heart failure

• Heart transplant

• An implantable device such as a defibrillator (ICD)

Cardiac rehabilitation encourages you to make lifestyle changes to help your heart to heal and become stronger – which means you can have a better quality of life. This type of rehab can help support you while you’re recovering from a heart procedure or prevent further heart conditions.  

This takes a holistic approach to help return an individual with heart disease to an active and normal lifestyle and to prevent the reoccurrence of a further cardiac event. Just as importantly, the process should help you understand your condition and how to live with it by making the appropriate changes to your lifestyle.

The guidelines and considerations for exercise after a cardiac event include really ought to be managed in consultation with your cardiologist according to your specific condition, but generally all programs being with low intensity, short duration physical activity and progress weekly according to your capacity. It’s important that you slow down or cease exercise according to your shortness of breath, and chest pain should be monitored closely. If applicable, it’s important to have your angina medication available while you are exercising. Importantly, your exercise physiologist can help to monitor your progress and ensure your safety along the way.