Work out and strengthen your immune system
Anna Magee
Read time: 5 Min
ith so much advice on how to keep your immune system healthy, it’s easy to be confused about what really works when it comes to beating and avoiding viruses.
“Your immune system is like a constellation of cells and molecules that reside all over your body,” says Dr Jenna Macciochi, an immunology lecturer at the University of Sussex and author of Immunity:
The Science of Staying Well (Harper Collins)
“These act like scattered listening posts, looking out for and preparing to combat anything that tries to break in and make you unwell, such as viruses, bacteria and toxins.” When you get ill, this system mobilises to deal with the invader. So, that high temperature or sniffle is your body’s immune response to a bug; its way of fighting it off.
We all know how important it is to maintain a strong immune system and that it can vary according to what we eat and other lifestyle habits. But did you know that regular exercise can also play a role? Find out how, as we look at the truth behind the fitness myths.
The Basics
Dr Roshane Mohidin
NHS GP and Vitality Healthcare Pathways and Behaviour Change Manager
“Although no foods or supplements can prevent or cure infections, eating a balance of food groups, a variety of fruit and vegetables, limiting salt and sugar and staying well-hydrated are key”
If you want to keep your immune system firing on all cylinders, take a holistic approach. First, a healthy diet is fundamental, says Dr Roshane Mohidin, an NHS GP and Vitality Healthcare Pathways and Behaviour Change Manager. “Although no foods or supplements can prevent or cure infections, eating a balance of food groups, a variety of fruit and vegetables, limiting salt and sugar and staying well-hydrated are key,” he says.
Adopting a good sleep routine will not only keep you feeling alert and energised, it will also help your body to support your immune system, too: “Prolonged lack of sleep can impair your ability to fight bugs,” says Dr Mohidin. “The amount of sleep we need is variable, but most of us need 8 hours.”
We all know it’s essential to wash our hands regularly to limit exposure to germs as well as to prevent spreading them. But we also need to protect our immune system itself, particularly because as we get older our bodies are less able to withstand viruses and bacteria and our response to vaccinations isn’t as strong. Our lifestyles affect our immune system, so it helps to be aware of what can strengthen it.
Why exercise matters
What many of us don’t always consider is that regular exercise is also essential to help keep our body fighting fit to fend off germs. “Regular physical activity helps initiate the mobilisation of immune cells within the blood circulation,” says Dr Mohidin.
“When you are exercising, you’re moving lymphatic fluid around your body,” Dr Macciochi explains. “This forces your immune cells to move around your body, performing their function of checking for anything going wrong.”
For some, the benefits don’t end there; exercise can even have an anti-ageing effect on your immune system. In one study, 55 to 79 year-olds* who were keen cyclists had similar numbers of T-cells [a type of white blood cell that protects the body from invaders] to people in their 30s.

7 Myths about exercise
We look at the truth behind the fitness myths – and discover some new exercise tips from Vitality Ambassador Dame Jessica Ennis-Hill.
Myth #1
cardio is king
Muscle mass starts to decline from your mid-20s and this directly impacts your immune system, as Dr Macciochi explains. “This is because healthy muscle tissue produces particular chemicals that keep your immune system rejuvenated.” That means that as well as cardiovascular exercise, we also need regular resistance training, ideally twice a week, he says. “This doesn’t have to be lifting weights, but anything that puts force on your muscles.” Light weights can help build muscle mass if the idea of lifting heavy weights doesn’t appeal to you.
Jessica says:
“People often think they have to go to the gym and do lots of heavy lifting to build muscle but you can build muscle using only your own body weight. Another great option is using Therabands (resistance bands). These can be used at home to build up strength in specific areas, including upper body, glutes and abdominals.”
Myth #2
A big bout of exercise is best
While any exercise is beneficial, the ideal for your immunity is regular, moderate and often. “Doing high intensity exercise for 45 minutes is fine, but if you spend the rest of the day sitting at a desk it won’t be as helpful for immunity as if you move around throughout the day,” says Dr Macciochi. “Try adding regular walking during the day and, for example, to your resistance training sessions twice weekly.”
Jessica says:
“I love walking and as I have become older, I have realised that you don’t always have to be pushing yourself hard. Going for a long walk at a decent pace and covering different types of surfaces can burn so many calories and increase cardiovascular fitness. If you want to try a walking workout, make sure you increase the pace as you go, and mix things up with a variety of terrains so you’re getting a good all-round workout.”
Myth #3
Moderate intensity exercise isn’t effective
When it comes to immunity, regular moderate exercise trumps repeated high intensity activity. “Studies have shown that moderate intensity exercise can support your immune system,” says Dr Mohidin. And it’s not only the traditional idea of exercise that counts; if you like to be active in different ways, “Brisk walking, gardening and carrying out housework at home are all good examples of moderate physical activity which you could do.” A study in the
American Journal of Medicine*
reported that women who did moderate intensity exercise for 45 minutes, five days a week, for a year had half the number of colds as those who didn’t. Researchers found that regular moderate exercise could lead to a higher number of infection-fighting white blood cells in the body.
Jessica says:
“I sometimes change my circuits to make them more moderate. So, instead of doing heavy dumbbells, I do bodyweight exercises based on reps instead of time; rather than doing as many as I can in 30 seconds of an exercise, I will do 8 reps instead. That makes it slightly less difficult and allows me to concentrate on technique. Lowering the pace and weight and focusing on your form on some days is great for building muscle.”
Myth #4
You can sweat out a cold
“It might sound plausible, but there’s no evidence you can sweat out your cold symptoms by exercising,” says Dr Macciochi. “Your immune system is going to raise your body temperature in response to an infection because this helps immune cells work better — it’s why we get fever,” she explains. “But this isn’t something you should try and induce by exercise.” So those feelings you get when you’re sick, such as not wanting to do much except rest and have a little chicken soup, are nature’s way of making you slow down, rest and recuperate.
Jessica says:
“This is your immune system’s molecules working on your brain to make you more withdrawn and lethargic, so you give your body a chance to heal.”
Myth #5
One size fits all in fitness (whether 18 or 80)
“Factors such as age, what you enjoy and whether you have underlying health conditions should help determine the exercise you do”, says Dr Mohidin. For most adults, 150 minutes of moderate exercise or 75 minutes of vigorous movement a week is recommended. “But an older adult with reduced mobility might do exercises that can improve their balance and strength, rather than activity that is particularly intense.” If you have underlying health conditions such as heart disease or lung diseases such as asthma, consult with your doctor about the intensity at which you should exercise to avoid flare-ups in your symptoms.
Jessica says:
“Strength work and resistance exercise is important throughout your life but you can tailor it to your ability. For over-60s, I would recommend Theraband (resistance band) workouts for providing strength as they come in different resistance levels. Light dumbbells are also great for providing some weight with less risk of injury. It’s also important for older adults to add elements of cardiovascular exercise to raise your heart rate regularly. That could be through going for a fast walk, cycling or swimming, which are all brilliant examples of low-impact cardiovascular exercise.”
Myth #6
Post-workout recovery doesn’t make a difference
If you tend to skip recovery-focused activities such as stretching and rest days, think again, because they’re essential for your immune system. And, as you get older recovery becomes even more important, says Dr Macciochi. So, if you’re over 40, take care of your body and ensure you recover well.
It will also count more if you’re not managing to maintain a healthy lifestyle. “Determining how much recovery you need after exercise will be personal but think about the other factors that could be impacting your immunity, such as stress levels and sleep,” she advises. To recover after exercise, make sure you stretch – this includes stretching dynamically before activity and statically after, and you could also try gentle yoga as part of your active recovery between fitness sessions. Also ensure you are eating enough. Fuelling your muscles with enough complex carbohydrates in the 24-hour period around your exercise sessions is key, says Dr Macciochi. For example, try to include wholegrains at each meal such as brown rice or wholemeal bread and pasta. Saunas might feel unnecessary when you’re busy but they may be beneficial too; one study* showed a single session could help increase circulating white blood cells. They can help flush out the inflammation that can lead to muscle soreness; “There’s a lot of evidence on the effectiveness of having regular saunas for general health,” says Dr Macciochi.
Myth #7
Rest days are a waste of time
Regular rest days are an essential way to help your body recover from exercise; “Without adequate rest between sessions, you risk flooding your system with stress hormones such as too much cortisol and this can switch off the immune response,” says Dr Macciochi. Studies* show the sweet spot for immunity is to exercise moderately, five days a week. In one study in the
British Journal of Sports Medicine
, people who did this almost halved the risk of coming down with a cold than those who were more sedentary. But listen to your body and if you’re tired, take that extra day off.

Jessica says:
“It’s important to listen to the signals your body is giving you, and having days when we let our bodies rest, recover and adapt to what we have done is also important as that is how we get stronger and better at our chosen exercise or sport. As an athlete I used to exercise daily. But now, I do circuits twice a week, and run at least once a week. Then, on other days I allow my body to recover with a mix of yoga, stretching and foam roller work, which is great for working into tightness and stiffness in the big muscles [such as the hamstrings] that can lead to injury.”
Want an advanced home workout that doesn't require lots of equipment?
We have a short workout that only needs one (securely placed) chair. Vitality Home Workout Coach Jenny Francis will help you work up a sweat. Adapt the moves to suit your fitness level. You could also team this with regular walking and resistance sessions
During lockdown 32% of women found they couldn’t exercise or take part in sports due to household tasks and caring duties* We want to reduce this ‘Play Gap’ and encourage and inspire women to fit exercise and playing sports into their busy lives. Follow us on
to see how we’re doing this.

* Research implications for women’s participation, Women in Sport, June 2020. Funded by Comic Relief.

Meet the Experts
Dr Roshane Mohidin
Dr Roshane Mohidin is an NHS GP and Vitality Healthcare Pathways and Behaviour Change Manager.
Dr Jenna Macciochi
Immunologist Dr Jenna Macciochi specialises in the impact of lifestyle on the immune system in health and disease. She is a lecturer at Sussex University, a qualified fitness instructor and a health coach.
Dame Jessica Ennis-Hill
Vitality Ambassador Dame Jessica Ennis-Hill is an Olympic champion and three-times World Champion heptathlete. She is one of Great Britain’s most successful athletes.
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