Competitive swimmers, slow turtles (you’re in good company), and anybody else who’s hanging out in chlorinated (or brominated) pools more than once a week,
I started swimming a couple years back when I pulled my hamstring (for the first time). Sure, I grew up “swimming” – playing marco polo, running and not walking on pool decks, wakeboarding on Lake Washington – but I wasn’t a swimmer. And you could tell… when I started, at first I’d swim 25 yards down and come up gasping for air and backstroke back to where I started. It wasn’t pretty. After a week or so I could string some laps together. And then I started to practice breathing to both sides and I looked like a fish out of water again... or at least a mammal in water who didn’t belong there.
But, during my recovery, swimming enabled me to workout more frequently and maintain some basic level of endurance since there’s no way you’re catching me on the hand-bike that every gym keeps around to fill space that could be used to do literally anything else.
Now, swimming is a regular part of my workout plans and a mandatory part of my triathlon training. But, the more I swim in public pools, the more I seem to catch colds or get swimmers ear... Why???
Chlorinated (or brominated) pools are a huge challenge to your microbiome. Chlorine and bromine and other compounds are used to kill bacteria and other microorganisms to reduce our risk of infection. So, your pool has chlorine, good news right? Well, yes (we don’t want to be swimming in a cesspool, so some way of limiting the growth/spread of nasty bugs is important).
But wait a minute…What’s this microbiome?
It’s the community of 10ish trillion bacteria that live all over your body and in your digestive tract. Those bacteria outnumber your human cells 10:1! There are more than 500+ different species in your gut alone. So, really you’re mostly bacteria… (like your poop!) (But, to be fair, while these bacteria cells outnumber our human cells, they’re a lot smaller and lighter, making up only 1-3% of our total body weight.)
All these critters serve a lot of important functions – from helping you break down your food, to producing important vitamins for you, regulating your immune system, making fats that keep your skin from drying out, and crowding out nasty critters that make you sick. They can even influence your mood and how you recover from exercise. This is why some scientists refer to humans as “Super Organisms”... because we coexist and function with this microbiome.
So, if we’re indiscriminately killing bacteria when we hop in a pool, that means we’re killing bad guys and good guys!
The good news is that your bacteria populations can bounce back quickly. But, if you’re consistently exposing yourself to a chlorinated pool, say at least once a week, you may be killing off too many good bacteria and changing the shape of your microbiome altogether. That could mean increased risk of infection like swimmers ear or the flu and even slower recovery times from workouts. Whether you’re an elite swimmer or just trying to get in shape, this means training less hard, less often and slower progress.
You can’t just stop swimming, though. The solution? Probiotics (and prebiotics). I’ll explain...
Probiotics are food sources of healthy bacteria: Greek yogurt, kefir, aged cheese, buttermilk, sour cream, sourdough bread, sauerkraut and other ‘krauts, kimchi, miso, tempeh, pickled and fermented vegetables, & more.
You can also get probiotics from supplements… more on that later because that’s a whole other can of worms.
A study back in 2013 tested the effects of daily probiotic yogurt consumption on the health and performance of endurance swimmers and found that those swimmers eating the probiotic yogurt (as opposed to the non-probiotic yogurt) were less likely to get respiratory infections and suffered shorter episodes of ear pain and shortness of breath when they did get sick.
When you exercise, especially at high intensity or for longer than 45 minutes, your immune system becomes naturally depressed. Now, in the long-run, more exercise typically means a healthier immune system. But, in the short-run, exercise can leave you open to pesky colds and infections. Consuming probiotics ensures a consistent stream of healthy bacteria into your microbiome. This can crowd out nasty bugs and also provide a much needed boost to your immune system... especially if swimming is a regular part of your exercise routine.
Plus, inflammation (your body's natural response to exercise and other forms of stress) is elevated post-exercise. Your muscles need re-building after being broken down during exercise, and inflammation stimulates your body's repair process. But, too much inflammation means a longer and less efficient repair process. A healthy microbiome that is consistently fed with probiotics will help optimize your body's level of inflammation for speedier recovery and gains from training.
Aside from just trying to add more beneficial bacteria to your system, how else do you keep that microbiome healthy?
You feed it with prebiotics… food for bacteria.Bacteria feed on fiber and other similar compounds found mostly in vegetables and whole grains. So, to feed your bacteria, eat your veggies and whole grains.
Everybody should be getting a good source of probiotics each day for general health as it is… even though most people don’t. For swimmers who use a public pool, and even for endurance athletes in general, a good source of probiotics each day is a must to keep the common cold at bay and improve recovery time between workouts. Different bacteria come with different foods so a variety of probiotic foods is best.
A good target:
One source of probiotics from food or supplements each day
A better target:
One source of probiotics with two different meals or snacks each day
The best target:
One source of probiotics with two different meals or snacks each day +
one of those sources within 30 minutes of swimming in a pool
My favorite quick & easy probiotic food ideas...
Greek yogurt breakfast parfait with fruit, granola, nuts and seeds
Greek yogurt based recovery smoothie
Kefir instead of milk at dinner
Sour cream on a burrito bowl or chicken tacos
Pickled/fermented vegetables like beet kraut on a side salad
Some of the research in case you're interested...
Gleeson, et al. Intense Exercise Training and Immune Function. Nestle Nutr Inst Workshop Ser. 2013;76:39-50.
Grice, EA, Kong, HH, Renaud, G et al. A diversity profile of the human skin microbiota. Genome Res. July 2008 18: 1043-1050.
The Human Microbiome Project Consortium. Structure, function and diversity of the healthy humanmicrobiome. Nature (486) June 14, 2012: 207.
Mukherjee, et al. Diversity of Bacterial Communities of Fitness Center Surfaces in a U.S. Metropolitan Area. Int. J. Environ. Res. Public Health 2014, 11(12), 12544-12561
Pedersen, et al. Recovery of the immune system after exercise. Acta Physiol Scand. 1998 Mar;162(3):325-32.
Salarkia, et al. Effects of probiotic yogurt on performance, respiratory and digestive systems of young adult female endurance swimmers: a randomized controlled trial. Med J Islam Repub Iran. 2013 Aug; 27(3): 141–146.