Improving the immune system with physical activity

The immune system keeps us healthy on a day to day basis by fighting any infection. The immune system is made up of proteins including antibodies, white blood cells, organs (such as the spleen) and other chemicals that help us prevent bacteria from attacking us.

Physical activity helps boost the immune system in many different ways. One of the most important ways in which exercise helps boost the immune system is by causing subtle changes in antibodies and white blood cells. The changes mean that the white blood cells and antibodies are able to move around the body more regularly, therefore detecting the origin of infection faster. If infection is detected earlier the immune system is able to start fighting illness faster. Not only does exercise allow white blood cells to circulate regularly around the body it also increases the number of white blood cells in the body – making it easier to fight the infection.

The beneficial effect of exercise on the immune system has been proven in many studies. The Medicine and Science in Sports and Exercise Journal reported that with 12 weeks of prescribed exercise individuals had better function in cells that are linked with the immune system than their inactive counterparts. The improvement in the immune system function is irrespective of age and has been proven in both older and younger individuals.

What type of exercise causes this boost in the immune system?

The immune system mainly benefits from a moderate level of exercise. Moderate exercise is something which causes you to be slightly out of breath and raise your body temperature for around 30 minutes. You may class this type of exercise as a 5 or 6 out of 10 on a difficulty spectrum where 10 is your are at your maximum. This is exactly the style of physical activity or exercise we prescribe at HSW.


Webmd: Component of the immune system’.

Medline Plus: “Exercise and Immunity.”

American College of Sports Medicine: “Exercise and the Common Cold.”

MedicineNet: “Exercise Restraint When Sick.”

Nienman. D.C., Henson. D.A., Guesewitch. G., Warren. B.J., Dotson. R.C., Butterworth. D. & Nehlsen-Cannarella, S.L. (1993) ‘Physical acitivty and immune function in elderly women’, Journal of Medicine and Science in Sports and Exercise.

Arthritis and physical activity

Arthritis is a common condition that affects a number of people. There are two different types of arthritis – Osteoarthrosis and Rheumatoid Arthritis. Although different, both forms are often characterised by joint pain, fatigue and lack of energy leading to less mobility.

Physical activity is key for those with arthritis as it is able to reduce susceptibility to muscle weakness, balance problems and further illness which can be caused by lack of activity.

With physical activity, you are able to improve your strength, posture, joint function and mobility. Although those with arthritis may find movement painful, it is possible to adapt exercise to ensure that this is not the case (it just takes good physical activity knowledge and a little imagination). Exercise at HSW will be adapted accordingly for those that find gripping, kneeling or bending challenging. This will mean you are able to strengthen your muscles around the effected joints. Strengthening the muscles that neighbour the effected joints will take the stress off your joints, resulting in less daily pain and more motion.

Flexibility is a contributing factor to better daily function, and is often an issue for those with arthritis. Physical activity and stretching have been proven to improve flexibility by lengthening fibres in the muscles. Both exercise and stretching also realign muscle fibres into an optimal position for movement. These changes reduce the perception of stiffness in areas affected by arthritis.

Those with arthritis often have less fluid in the joints than those who are not affected by the condition. Having less fluid between the joints causes a buildup of friction during movement. The buildup of friction is one of the factors which creates the feeling of pain and stiffness. It is widely recognised that physical activity instigates the joints themselves to release more fluid, therefore reducing the friction upon movement of the joints. This ultimately reduces the level of pain which means you are able to move with more freedom.


Ellapen. T. J &Paul. Y. (2017) ‘Exercise-induced physiological lubrication mechanisms dissipating arthritic joint pain’, South African Journal for Research in Sport, Physical Education and Recreation – Exercise-induced physiological lubrication mechanisms dissipating arthritic joint pain.

Exeter University Sport and Exercise Science department – clinical exercise prescription – arthritis

Physical activity and resting heart rate

The heart is one of the most vital organs in the body. Heart rate changes regularly depending on what you are doing – it will be higher during physical activity and lower when lying down. Resting heart rate is the number of beats per minute your heart makes after you have been resting for a short period of time.

One of the main benefits of exercise is a stronger heart. Exercise or physical activity causes the heart to adapt just like it does any other muscle. During a period of physical activity/exercise the heart is stimulated to beat faster and as the heart learns to deal with the increased stimulus it causes long term changes in resting heart rate. The heart improves its ability to contract/beat and it is able to pump the blood round the body more efficiently.

Cardiac output is a measure of the volume of blood pumped out of the heart per minute. Cardiac output is maintained by heart rate and the amount of blood that is pumped out of the heart in a single beat. As the heart is now more effective and pumping out more blood per single beat the resting heart rate is able to reduce without reducing the cardiac output (volume of blood pumped out the heart per minute). This means the heart is under less pressure.

Reducing resting heart rate has been linked to a longer and healthier life, but why?

Reducing resting heart rate has been linked to a longer and healthier life. This is because every heart beat puts a slight amount of stress on the heart and the arteries. Therefore, the less times the heart beats in a minute the less stress the heart is under. This reduces the chance of complications if you do have heart disease or reduces the chance of getting heart disease in the first place. The great thing is that exercise can modify your heart rate and reduce it. By reducing the heart rate by 20 beats per minute can reduce your risk of heart disease by between 30% and 50%.

Most importantly taking pressure of the heart by reducing our heart rate means we are less tired. Being less tired during everyday activities allows us to conserve our energy for activities we want to take part in, whether this walking or running, playing with children, getting upstairs or completing a charity bike ride.


Arnold. J.M., Fitchett. D. H., Howlett. J. G., Lonn E. M. & Tardiff. J. (2008) ‘Resting heart rate: a modifiable prognostic indicator of cardiovascular risk and outcomes’ The Canadian Journal of Cardiology.

Harvard Health Publishing (2008), ‘Slower heart rate may translate into longer life, reports Harvard Heart Letter’ Harvard Health Publishing, Harvard Medical School.

LeWine. H (2017) ‘Increase in resting heart rate is a signal worth watching’ Harvard Health Publishing, Harvard Medical School.

Exercise helps anxiety, depression and mood disturbances.

Key endorphins that are associated with the reduction in depression and anxiety are released during and after exercise. This process is called neurogenesis.

Neurogenesis occurs in the brain when you take part in physical activity or exercise. The hormones that are released by the brain during physical activity are the same as the ingredients that are in the medication prescribed by your doctor used to reduce your anxiety and depression symptoms. The endorphins that are released also drastically help you manage your stress levels. Exercise can become your drug-free treatment.

Exercise is great as a sustainable source of these key hormones/endorphins and does not have the side effects of taking daily medication. With exercise, you are completely in control of your mood, and it is you that is making your body feel stronger, more in control and ultimately happier rather than a drug. YOU can build your confidence and your happiness yourself.

There are numerous mechanisms for how exercise can reduce anxiety and depression and below we will outline two:

Endorphin and hormone regulation:

Chronic stress has been linked to reduced release of hormones associated with anxiety and depression. It is suggested that the reductions in these hormone levels reflect not being able to cope with a situation. Not being able to cope with a situation increases the bodies demand for these hormones. It has been proven that regular aerobic exercise increases the hormones in the brain, and has similar effects as antidepressants. Therefore, exercise can help the brain release enough hormones to keep up with the bodies demand. This results in normal levels of the hormones throughout the body and reduced negative mood symptoms during stressful situations.

Self-efficacy (self confidence):

Self-efficacy is defined as a personal judgement of how well one can execute a successful course of actions or deal with a specific situation. Exercise can help one improve their self-efficacy by enabling them to trust their ability to manage potential ‘threats’ or ‘stressors’.

As fitness or function improves the individual receives feedback from their body which tells them they are better able to deal with situations which may previously have caused them mental or physical pain. Therefore, self-efficacy has increased, leading to greater self-confidence and reduced levels of anxiety or depression.

In health science research carried out by Katula, it was proven that moderate levels of exercise as opposed to high or low levels of exercise had the greatest effect when reducing anxiety.