Exercise and your immune system – what’s the link?
Quick Overview
- Exercise helps the immune system locate and destroy viruses and bacteria
- Sticking to an exercise habit long term decreases your likelihood of developing infections
- Moderate-intensity exercise increases immunosurveillance – enhancing the activity of specific cells of the immune system
You don’t have to be a dedicated gym junkie to reap the benefits of exercise. Exercise immunology has uncovered some remarkable connections between exercise and the immune system.
Not only does the research back up what we already know – that exercise can make you feel great but it’s also proven that exercise is important for your overall health, including your immune cells. Some of the findings in this area of research also reveal new information that you may find surprising.
How does exercise improve the immune system?
Exercise, sunshine and fresh air not only improve your mood and get the blood pumping, but they also support the healthy function of the immune system. A 2018 study conducted at the University of Bath found that exercise helps the immune system to locate and destroy viruses and bacteria.
Longer term results of regular exercise include reducing the changes that typically happen to the immune system as the body ages, helping to decrease likelihood of developing infections.[1]
Exercise for your gut… but not the way you might think!
When it comes to preventing infection we don’t often think about gut health, but it’s estimated that around 70% of the immune system is in the gut.[2] How does exercise tie into this? Research shows that people with higher levels of aerobic fitness also tend to have a wider variety of healthy bacteria in their guts, regardless of their diets.[3]
Exercise can also increase the amounts of healthy bacteria that produce a substance called butyrate, which is an indicator of both overall health and a healthy gut.[3]
So, how exactly should you exercise to build immunity?
How to exercise to build immunity
When it comes to boosting your immune health, your exercise goal should be to move at moderate intensity for up to 60 minutes at a time at least three times a week – but to give yourself a break or take things easy when you’re run down or over-tired.
Moderate-intensity exercise of no more than 60 minutes increases ‘immunosurveillance’. That is, it enhances the activity of specific cells of the immune system so they function on high alert, looking for bacteria and viruses.[4]
Another reason that your immune system activity is elevated during and after short moderate-intensity exercise sessions is that short bursts of activity prevent stress hormones like cortisol from reaching the high levels in the bloodstream that are associated with inhibition of immune system function. To reap these benefits, it’s recommended that you exercise for less than an hour at a time.[4]
Simple exercise to boost the immune system
So, what does ‘moderate exercise’ look like? Moderate activity should increase your heart rate by 50-60% compared to when you are resting and might include:[5]
- Walking 3km in 30 minutes
- Biking 8km in 30 minutes
- Swimming laps for 20 minutes
- Running 2.5km in 15 minutes
- Doing water aerobics for 30 minutes.
- Playing volleyball for 45 minutes
- Playing basketball for 20 minutes
- Jumping rope for 15 minutes
- Walking stairs for 15 minutes
Exercise for the immune system
It’s important to remember that exercise is a personal thing, so your main focus should be on exercising to your current ability.
If you’ve gotten a little too cosy on the couch over the past month or year and need to start slowly, that’s okay. Make it your priority to move your body daily, whether it’s a 10-minute walk around the block, 20 minutes of gentle stretching or some leisurely laps at the local pool. If you’re someone who loves to set yourself a challenge, look around at local clubs and gyms for one that gets you excited and motivated.
Don’t overdo it
If you love to exercise but you’re struggling with your immune system and/or energy levels, consider these questions:
- Do you feel exhausted after a workout and find it hard to recover?
- Are you doing one or more hours of intense exercise every day?
- Do you ‘forget’ to factor in at least one rest day (this can be active rest such as a gentle walk or stretching)?
- Do you have a lot of stress in other aspects of your life such as work, family, or relationships?
If you answered yes to any of these questions, you could be overdoing it. Over-exercising and not getting enough rest robs your body of the chance to recover. Too much exercise can also be stressful to the body, leading it to produce higher amount of the stress hormone cortisol, which, as mentioned above can have detrimental effects on your immune function.[4]
Balancing high-intensity workouts with moderate to lighter workouts can do wonders for your immune health. And you don’t have to train yourself to exhaustion in order to reap the benefits and have a good time doing it.
Your week of workouts might look something like this:
- Monday: 30-minute jog or high intensity interval training (HIIT)
- Tuesday: gentle one-hour yoga class
- Wednesday: 45-60 minutes of swimming laps
- Thursday: a walk with your dog along a local bushwalking track
- Friday: a boot camp with friends in the park
- Saturday and Sunday: gentle stretching, gardening, a leisurely walk through the markets
If you’re new to a particular exercise or haven’t exercised in some time, it’s always best to check in with your GP and get the all-clear before you start – then take it slowly to avoid injuries to muscles that may not be used to the movements.
Exercising for immunity involves a degree of mindfulness and respect for what your body needs or is feeling from day to day. Start by choosing an activity you love and go from there.
References:
- Simpson RJ, et al. Exerc Immunol Rev 2020;26:8-22.
- Vighi G, et al. Clin Exp Immunol 2008;153(1):3-6.
- Estaki M, et al. Microbiome 2016;4:42.
- Nieman DC. Journal of Sport and Health Science 2019;8(3):201-217.
- Cleveland Clinic. Last updated Oct 2020, accessed June 2021 from https://health.clevelandclinic.org/what-does-moderate-exercise-mean-anyway/