Want the immune system of a 20-year-old when you're 80? WORK. OUT. MORE.

This article was originally published March 22, 2018.

With flu season behind us and warmer weather promising to settle in (soonish), your mind may be turning to long walks and languid bike rides in the sun — as well it should. More exercise, science continues to tell us, is exceptionally good for you. It can even mitigate some of the ill effects of ageing by keeping us fit, toned, happy and otherwise healthy. While no correlation has been made between crunches and crows feet, new science has confirmed that you can at least keep your insides in their prime long after you've entered the winter of your life. You just need to commit to working out more. A lot more.  

UK researchers have found that elderly people who get plenty of exercise seem to be staving off the expected decline of their immune systems… by about 60 years. Data yielded from 125 long-distance cyclists, many of whom were in their 80s, showed that they had the high-functioning, infection-thwarting immune systems of 20 year olds. Feel free to hop on the stationary bike that's been collecting dust in your basement as you read the rest of this.  

Professor Janet Lord, study co-author and director of the Institute of Inflammation and Ageing at the University of Birmingham, explains that "the immune system declines by about 2-3% a year from our 20s, which is why older people are more susceptible to infections, conditions like rheumatoid arthritis and, potentially, cancer." But her data shows that the steadily weakening immune response that would normally leave us increasingly vulnerable as we age is far from a fate we must all simply accept. So long as exercise is a priority. "Because the cyclists have the immune system of a 20-year-old rather than a 70 or 80-year-old, it means they have added protection against all these issues," says Lord.

The health boon for the ageing endurance cyclists studied, explain researchers, hinges on the production of a lymphocyte (or white blood cell) known as a T cell. Side note: endurance cycling events typically range from 100 km to 300 km rides. For context, 100 klicks on a bike will likely take you about 3 hours — so do ease in slowly if you're inspired but it's been a long winter of sofa comas.

T cells get their name from the small organ living in your chest cavity that produces them: the Thymus gland. They're just one type of white blood cell that scours your body for trouble. The other type of white blood cells are the B cells developing in your bone marrow which produce antibodies. The two, in part, make up the innate immune system: the in-house guard that's meant to keep you safe from infection by attacking interloping organisms like bacteria and viruses. The reason T cell counts drop as we age is that our Thymus glands tend to shrink over time – making us more susceptible to illness and even lowering our response to vaccines like a yearly flu shot. Age really does do a number on us. The study establishes that "it is widely accepted that aging is accompanied by remodelling of the immune system including thymic atrophy and increased frequency of senescent T cells, leading to immune compromise." Senescent cells are simply older cells (aka zombie cells — yes, really) that contribute to the majesty of the ageing process. Increased physical activity, says science, seems to stall that process.

Consider that a control group of older but inactive adults were found by researchers to produce very few T Cells by comparison to their bike ride loving counterparts. "T-cell frequency was lower in healthy old sedentary adults compared with young donors…" but "...[t]his decline was not seen in the master cyclists as their T-cell frequency was higher than the inactive elders … and not different from the young adults," reads the study.

Dr. Norman Lazarus, at King's College London, who co-authored the research confirms that "if exercise was a pill, everyone would be taking it.  He asserts, as other have before him that "it has wide-ranging benefits for the body, the mind, for our muscles and our immune system." Presumably Lazarus knows that exercise is already something of a pill, and a bitter one for many. But we are truly meant to move throughout our lives.

Professor Steve Harridge, who also took part in the study, maintains that "being sedentary goes against evolution because humans are designed to be physically active." Thankfully for the less enthused among us Harridge also reminds us that "you don't need to be a competitive athlete to reap the benefits — or be an endurance cyclist — anything which gets you moving and a little bit out of puff will help." Out of puff. Hmm, wonder if he's British?

The research adds itself to other studies like it that aim to improve and ideally extend the viability of immune systems in our ageing population. Exercise, yet again, could be one way to leverage that. That said, should you need more aesthetic reasons to buy a bike, still another paper based on the same data as the immune function study showed that older cyclists experienced no age-related increases in body fat. They also enjoyed absolutely no loss of muscle mass or strength. For what it's worth, I'm getting my bike with a jaunty basket and a bell.   

If you've been hibernating since you got your fall flu shot, there are worse ideas than shaking off the winter months with a brand new road bike. It might at least up your chances of side stepping the dreaded summer flu bug. It's that or you take your chances with your shrinking thymus.

Marc Beaulieu is a Montreal writer, producer, performer, professional host and mental health advocate whose one true love is weird news.