Let’s talk about exercise in times of COVID19:
Light to moderate exercise extends your life expectancy through several ways, and one of them is by helping support the normal function of your immune system. They say you should aim for 150 minutes of exercise per week, that’s 2.5 hours, – which is roughly 20 minutes every single day of the week or 30 minutes per work day.
Some say going overboard or doing strenuous exercise can stunt the function of your immune system, but I have some news for you [FLASHING # FAKENEWSALERT! on screen] – yup that’s misinformation or what I like to call “mythformation”. There is no solid evidence to back this – in fact it’s more likely that an infection you catch during or after exercise is linked to psychological stress, bad eating habits, poor sleep, traveling, or exposure to pathogens at large social gatherings like marathons.
Before we jump into the science, I want to mention that even if you can’t exercise daily, simply getting your daily steps in has a big impact. This is good news because, throughout past, present or future lockdowns, most of us are limited with how many times or the length of time we can spend outside, and some of us are just too tired or lacking motivation to stretch our legs and get our bodies moving. But, missing out on that run, cycle, Zoom cardio class, or long walk does not mean today is a fail in terms of exercise. Simply walking around your living space throughout the day benefits your overall physical health – A recent study has shown that taking 8000 steps throughout each day can half your risk of dying over a ten-year period compared to taking 4000 steps per day. But, interestingly, it does not matter how many of those steps you take per minute. In other words, it doesn’t matter whether you take 18 or 150 steps per minute – what counts is the total number of steps in one day.
So, back to your immune system.
How does exercise help support its function and counter some of the effects of ageing, undernutrition, malnutrition and conditions such as obesity and diabetes?
These all have something in common: inflammation. And this is also why the elderly and those of you suffering from any of these conditions are at a higher risk of developing one of the serious complications of COVID19: acute respiratory distress syndrome - ARDS. You can check out my second video in this series where I describe this in more detail, as well as some of the science jargon I’m going to use here.
Studies have shown that exercise can reduce your risk of developing ARDS. This is because exercising causes your muscles to produce an antioxidant enzyme called extracellular superoxide dismutase (yeah that's a mouthful!). High amounts of this enzyme are usually found in your lungs, so by increasing its levels with exercise this can counteract the high amounts of inflammation caused by COVID19 and therefore reduce your likelihood of this turning into ARDS.
Inflammation plays such a big part in ageing, obesity, diabetes… the list goes on. But particularly so in ageing and all the diseases that come gift-wrapped with ageing. We are all ageing right now, so we are all affected by inflammation at some level. This phenomenon even has its own name: inflammageing. The older you get, the more significant this becomes. It’s why 40-60% of those over the age of 65 have such a poor response to vaccinations. But lifelong moderate exercise can improve this response and help restore immunity by reducing inflammageing. How? The shrinking of your thymus slows down, so you’re able to maintain sufficient levels of immature Killer T-cells which can then mature to fight different infections, and the activity of these immune cells is also improved. Even brief bouts of exercise are a great anti-inflammatory, especially for people living with chronic viral infections such as HIV, or those suffering from cancer. When you exercise, your immune cells leave your bloodstream to travel into your tissues where they are more likely to bump into infected cells or body cells that have become cancerous.
Now, If you are young and healthy like me, you still need to exercise regularly to not only help your immune system function at its best but also as an insurance for your future immunity!
In my next video of this series, I’ll dive into how sleep hygiene can impact your immune system.
But for now, stay safe, sane and sanitised! Written by Dr Elisabeth Thubron - Head of Science & Research