One of the first real big shocks to a new runner is how sore your legs can be after upping your running distance. Naturally, being the 21st century and all, one of the first things that new runner will want to do is run (pun totally intended) to the internet to either Google or ask running strangers how to cope with the pain.
But asking the internet will give you hundreds of different answers. Every dedicated runner has their preferred recovery trick, whether there is any proven benefit to that trick or not. Compression socks. Foam rolling. Ice baths. And the one I want to talk about today: Epsom Salt baths.
The claim is that by soaking in a bath with Epsom salts, otherwise known as magnesium sulfate, will help prevent and heal muscle soreness, joint pain, and detoxify the body.
But how does it work?
Magnesium is a critically important mineral found in the human body, and is heavily involved in protein synthesis, energy production and detoxification. The unofficial claims are that, as a whole, humans are deficient in magnesium. Therefore, by soaking in a tub full of Epsom salt, the magnesium and sulfate are absorbed through your skin, and magically aide the protein synthesis and detoxification resulting in a much less sore YOU.
Sounds pretty logical, right?
Except that the human body doesn’t exactly work that way. Our skin is relatively waterproof, it’s how we keep all of the good stuff inside of us and the bad stuff out. If our skin wasn’t essentially non-permeable, we’d be constantly struggling to keep out toxins and keep in, well, everything we need in order to survive. Therefore, the idea that a quick soak in a tub can both cause minerals we are supposedly deficient in to soak into our body, all while the bad “toxins” soak out, seems a little far fetched.
In fact, a quick Google search, or even an extensive one for that matter, will turn you up empty handed with reputable, peer reviewed research that says magnesium and sulfate are absorbed across the skin, or that Epsom salt baths actually work as a means of post workout recovery. In other words, science does NOT currently back the claims of Epsom salts when it comes to sore joints and muscles.
So is an Epsom salt bath soak a complete waste of time?
There is no denying that a nice, hot bath can help relax you, both mentally and physically. This of course, is the complete opposite concept of the post long run ice bath, which I would argue is not relaxing AT ALL…even though it still may help ease post run soreness.
But let’s get back to the hot bath.
Adding essential oils or aromatherapy salts to your bath an help you mentally unwind from the stressors of training, and life in general. Relaxing your mind may help you relax your muscles, which can help soothe stress, aches, and pains associated with hard training. And some research even shows that warm muscles are likely to be less tense than cold muscles.
Plus, there is always the argument of the placebo effect. If you feel better after soaking in a hot tub full of Epsom salt, then it most likely isn’t going to hurt you.
So in conclusion, I’m sorry to break it to all of you devout Epsom salts fans, but it appears at this time that the use of Epsom salts for healing sore muscles is likely an old wives tale. That said, you ran hard, you’re training hard, so if you want to relax by taking a nice arm bath, then do it. You’ve earned it!