What is the purpose of exercise?


We all lead very busy lives. We think there are not enough hours in the day to do all the things we need to do, let alone all the things we would like to do, so we tend to cut corners to fit everything in and one of the first things we tend to skimp on is exercise. Yet exercise plays a vital part in a healthy, well-balanced life, so to encourage us all to take some time to do it, let’s look at the meaning of and evidence for exercise and ask ourselves: what is the purpose of exercise?

What is the meaning of exercise?

The word exercise comes from the Latin: ex – thoroughly and arcere – to keep in or away; which became exercere – to keep busy, practise, and then somehow morphed into the Middle English exercise – the application of a right.

In a general sense, exercise means:

  • an activity requiring physical effort, carried out to sustain or improve health and fitness.
  • an activity carried out for a specific purpose.

We exercise for many different reasons, and perhaps looking at the evidence for exercise and the purpose of exercise can support us to find the time in our busy days to do it.

The evidence for exercise

Dr Michael Evans has made a great short video on exercise called “23 and 1/2 hours: What is the single best thing we can do for our health?” which states the following.


  • reduces rates of pain and disability in people with knee arthritis by 40%
  • reduces progression to dementia and Alzheimer’s by 50%
  • reduces progression to frank diabetes for those at high risk by 58%
  • reduces risk of hip fracture in postmenopausal women by 41%
  • reduces anxiety by 48%
  • reduces depression by 30-47% in a dose-dependent way
  • reduces risk of death by 23%

These were the standout findings for me:

Exercise is the number one treatment for fatigue.

This busts the myth that we are too tired to exercise… the best thing we can do if we are feeling fatigued is to move our bodies!

Low fitness is the strongest predictor of death.

The Aerobic Centre Longitudinal Study compared risk factors including hypertension, diabetes, smoking, obesity and cholesterol, and despite all the evidence showing that each of these factors increased risk of mortality, lack of exercise was the highest predictor of death. We work so hard in medicine to keep people healthy and well or at least alive. We actively treat diabetes, cholesterol and hypertension but how many of us encourage our patients to exercise regularly and take the time to explain that it is as simple as going for a short walk every day? And how many of us model this behaviour ourselves? 

Exercise improves quality of life.

Nearly all of us think our lives could be better… if we could just make more money, have more time, go on more holidays, improve our relationship, whatever it may be… but what if it were as simple as going for a walk? We may be busy with work, kids, or in pain, overweight, depressed, exhausted, or all of the above, but what if going for a walk could be the start of turning it all around?

If exercise is the medicine, what is the dose?

To a point, more exercise is better, but after 20-30 minutes a day, the rate of return is less, and even a little is better than nothing. In the Nurses’ Health Study, just one hour a week reduced the rates of heart disease by half.

You don’t have to do it all at once – you can break up the 30 minutes a day into three blocks of 10 minutes and it still has a beneficial effect. The Osaka gas company study of 8000 employees in Japan in the 1990s showed that for every 10 minutes of daily walking to work, there was a 12% reduction in the risk of high blood pressure.

The National Institute of Health and Care Excellence guidelines state that the evidence suggests that the minimum amount of physical activity that an adult should do a week is 150 minutes of moderate or 75 minutes of moderate-to-vigorous physical activity split over 5 days during a week. In addition, adults should be doing strengthening exercises on 2 days a week.

Why do we exercise?

Looking at the reasons why we exercise may help us to understand why we don’t, when we all know that it improves our health and wellbeing and our quality of life.

Do we exercise to:

  • Achieve something? To look good/get fit/lose weight/tone up/be strong etc.
  • Assuage guilt? To burn off that ice-cream/chocolate cake/bottle of wine etc.
  • To compete? With our partner/friends/colleagues/team/town/state/country.
  • Get somewhere? Run that race/cycle that ride/climb that mountain/walk that trail.
  • Because we think we should? Others are doing it/our partner wants us to.
  • To be with friends? Is it our way of being social?
  • Because we have been told it improves our health and chances of survival?

Or do we do it because we enjoy being in this body of ours and we love to move it and care for it?

These are very different ways of looking at exercise, which can lead to very different ways of going about it.

Exercise can be yet another thing we have to tick off our long list of things to do.

Or it can feel like a chore, a duty, or even a punishment.

We can flog ourselves to try and make up for a big night out, or an indulgent holiday.

We can use it to vent our anger and frustration or to numb ourselves, or even as our daily fix.

It can leave us feeling sore, tired, exhausted even, and in need of a coffee/cake/drink or rest to try and recover from it.

Or, it can be a way of moving that brings us in to our body, allows us to enjoy it, and can be done in a way that celebrates and cares for the body while keeping it strong, supple and vital.

Exercise need not be hard work and it need not take a long time. A 10-15 minute walk in the morning before work, at lunchtime, and at the end of the day is all it takes to move our body for the 30 minutes a day that are recommended for our health and wellbeing.

You can walk with your partner in the morning and talk about your day to come, or walk in the evening and talk about the day that was, or walk as part or all of your daily commute, or get out and walk in your lunch break instead of checking out on social media.

A gentle swim, light weights, and cardio done in connection with you will support you and leave you feeling more energised rather than even more exhausted and drained.

And don’t think you are too tired to exercise. There is nothing more energising than going for a gentle walk, and no matter how tired you are, you will feel better for it. It is a great way of starting and ending the day, of letting go of anything you have taken on and leaving you feeling refreshed and ready for the next phase of your day. Exercise: give it a go!


“Walking is man’s best medicine.” (Hippocrates)


  1. What good timing to read this, and I have a question. What is the link between knee arthritis disease and exercise? What actually happens in the body that exercise reduces the potential risk of arthritis?

    • Hi Viktoria,
      thank you for your comment and that is a great question. Neither Jane nor I are knee arthritis experts and we do not offer medical advice on this site…Perhaps you would like to take your question to your friendly local doctor!
      with love, Anne


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