We're always being told to exercise and if you've not been active for a while, you often hear you should see a doctor before you start.
But finding the motivation to get moving can be tough enough on its own.
Add to that the need to get yourself checked over first and there's a risk some of us might decide it's all too hard.
Is medical clearance really necessary?
In some cases it's definitely advised, says Jeff Coombes, professor of exercise science at the University of Queensland.
"It's a balancing act," he says.
"We don't want to put up barriers to stop people from starting exercise programs, but at the same time, we want it to be safe."
When is exercise risky?
While, in general, exercise is one of the best things you can do for your mind and body, Professor Coombes says there are certain health conditions that can make being active more risky.
"The major event we're trying to avoid is a cardiovascular event — a heart attack or stroke," he says.
If you've had a heart attack or stroke in the past, have been diagnosed with a heart condition, or have symptoms suggesting one, seeing a doctor first is highly recommended.
Examples of heart conditions include heart rhythm problems, heart infections, and heart defects you were born with.
Unexplained chest pain and dizziness or loss of balance may indicate undiagnosed problems relating to heart attack and stroke risk, so these indicate the need for a check-up too.
Recent asthma attacks requiring a GP or hospital visit, trouble controlling your diabetes, and problems with muscles, bones and joints may also be "red flags" that require further investigation, Professor Coombes says.
What's the risk of heart attack during exercise?
While the risk of a heart attack or stroke during exercise is low for the population as a whole — about one in 15,000 — it might go up to one in 2,000 if you have coronary artery disease (where the arteries supplying your heart muscle are narrowed or blocked).
Having untreated high blood pressure or cholesterol in turn raises the odds of these narrowed or blocked arteries.
"The more risk factors you have, the more the risk goes up," Professor Coombes says.
"But the risk of developing narrowed or blocked vessels in the first place is around one half for those who are physically active.
"Therefore, we need to be doing everything to encourage and support people to exercise."
Almost always, some type of exercise will still be possible whatever your health problem, but advice may need to be tailored to your particular needs.
Take a quick quiz
The risk of injury or death from exercise can never be completely ruled out, but it can be minimised by answering a short questionnaire called the Adult Pre-exercise Screening System developed to help you work out if you need medical advice before you start.
There's an accompanying User Guide you should read too.
The tool has been designed so exercise physiologists, exercise scientists, and personal trainers can use it with their clients.
But you can also do the first stage of the questionnaire on your own and, depending on your answers, that may be enough to indicate you are not at high risk and can start exercising at a light to moderate intensity without further guidance.
You might expect age or obesity to be the subject of points in the questionnaire, but by themselves, they aren't significant factors that affect the safety of starting exercise, Professor Coombes says.
Around 10 per cent of obese people have no other cardiovascular risk factors, and for them, starting a gradual program of light to moderate exercise is considered relatively safe.
Start exercising gradually
Whether obese or not, Professor Coombes says the safest way to start getting active is with bouts of 10 minutes at a light to moderate intensity.
This means walking (or some other activity) at a level where you can still have a conversation.
"You could then try to build that up to maybe two bouts of 10 minutes or 10 minutes plus five," he says.
"Start trying to do this every second day — so three times a week — and work your way up.
"Your goal is to eventually complete 150 minutes each week at a moderate intensity."
Included with the questionnaire is a handy table that describes how to tell if the activity you're doing is at a light, moderate, or intense level.
However, if you answer 'yes' to any one of the first six questions in the questionnaire, you're advised to see your GP for further assessment or advice before starting exercise.
Article from ABC Life