Should sub-3 runners take epsom salt baths?
Sub-3 runners don’t take bubble baths – they “soak their legs.” Just don’t ask too many questions about the 20kg sack of salts by the door.
Before committing to sub-3 training, I honestly can't remember the last time I had a bath. Showers were quicker, cleaner and far more compatible with pretending to be a functional adult. But once I started clocking consecutive 130km weeks, I needed new ways to recover – and short naps, relentless protein and stretching only got me so far.
That’s when I found myself, reluctantly, “soaking my legs”.
Let’s be clear: it’s a bath. A big, hot, steamy bath. And not just any bath – an epsom salt bath, that time-honoured runner’s ritual involving scooping in a few generous cupfuls of white crystals and convincing yourself you’re doing something serious for your legs, not just indulging in a spa treatment while your family tiptoes past the bathroom door in disbelief. To this day, I still find it hard to say out loud that I’m having a bath. So I don’t. I say I’m “soaking my legs”.
And you know what? It works. Not in a clinically proven, peer-reviewed, magnesium-absorbing-through-the-skin kind of way – even I’m sceptical of that. In fact, despite the popularity of the practice, there’s almost no solid scientific evidence that the magnesium sulfate in epsom salts can be absorbed through the skin. A small 2006 study from the University of Birmingham suggested it might be possible, but it’s never been replicated and remains speculative at best.
What is proven is that warm water works. It improves blood flow, relaxes muscles and promotes recovery by activating your parasympathetic nervous system. In short, it calms you down. And after 30–45 minutes submerged, there’s no question that my legs feel better. Fresher. Almost glowing. Like they’ve hit some kind of muscular reset button. Especially after a hard race, it’s one of the few things that reliably makes me feel ready to take another hammering in an upcoming session.
I still buy epsom salt in 25kg sacks. I still scoop in a few cups, even though I suspect the hot water is doing 90+ percent of the work. And I still call it “soaking my legs,” because “having a bath” still feels like a guilty pleasure, not a recovery tool.
Scientific evidence? Minimal. Risk of harm? Pretty much none. Recovery boost? Undeniable - even if it’s just habit, ritual and a dash of placebo. And in sub-3 training, sometimes that’s more than enough.
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