Hi Rondal (aka ‘puddles’),
You sound a bit like me, a HEAVY sweater! Like you, I know all too well the perils of a floor soaked with ‘puddles’ following a session on the trainer…
It’s a good question you ask and it won’t be a case of focusing just on how salty your sweat is or how heavily you sweat, but rather on both.
Ultimately, there are two main pieces of the puzzle when looking at sweat - Sweat Rate (how much fluid you’re losing via sweat) and Sweat Sodium Concentration (the concentration of sodium in that sweat).
So, the most important thing to emphasise here is that the sodium concentration of your sweat is largely genetically determined, regardless of whether it’s hot or cold outside, but the total amount you sweat will change according to things like the temperature you’re exercising in, your own fitness levels etc.
I’ve attached a handy picture which summarises the relationship between sweat concentration and rate, and your ultimate net losses:
What this picture highlights is the intertwined relationship between the concentration of what you’re losing and the volume of what you’re losing, and how your net losses could still be quite high when compared to someone who is a particularly salty sweater.
For example, I’m not a particularly salty sweater (I only lose 696mg of sodium per litre) but my sweat rate could be around 2 litres per hour in certain conditions. So, if I did an hour workout on TrainerRoad, my net loss would be around 1392mg for the hour.
If our founder Andy did the same session on TrainerRoad for an hour and he has a very salty Sweat Sodium concentration of 1,800mg per litre of sweat but only loses 0.8 litres of sweat, then his net losses for that hour wouldn’t be massively different to mine (~1440mg).
So, even if the concentration of your sweat is relatively low, your net losses could be quite high. It’s never one or the other, it’s an intertwined relationship between making sure you’re replacing enough sodium and fluid for a certain session or race.
Having said that, it’s impossible to replace 100% of what you’re losing and what you’re looking for is that middle ground/sweet spot, which you’ll ultimately discover through trial and error during your training sessions. For more on how much dehydration you can tolerate and the upper limits, it’s worth checking out this blog.
I’ve included a blog on the forum previously about how to measure your own sweat rate which I can pass on if you need, and I hope the above information helps.
Apologies for the delay in getting back to you, I’d only just picked up your message on here but feel free to reply to this message or email us at Hello@PrecisionHydration.com to discuss your sweat losses further.
Many thanks,
Chris