As I mentioned in my post A recovery lesson learned the hard way, recovering properly after a run is hugely important. Especially if you don’t want to turn into a delusional rage-monster at risk of passing out at any moment. Not that I speak from experience, or anything …
It’s not only important to refuel but also rehydrate. Before I started the UofC Marathon Training Program, rehydrating properly involved a lot of guesswork.
On a day-to-day basis I think I am pretty good at continually drinking water at work, at home, in the car etc. But when I found out how much fluid you need to take in to rehydrate after a workout, I realized I had some work to do.
To know how much water you need to drink after a workout, you first need to know how much you sweat. For me, I knew the answer would be A LOT. I am one of those people who embarrassingly sweats while sitting down doing nothing, or while walking up a small fight of stairs or when I am nervous. When I go to hot yoga I usually stand beside one of the dudes because they are the only ones there who out sweat me. Gross, I know. But I am used to it.
Surprisingly it’s actually really easy to figure out your sweat rate. The hardest part for me was that I had to purchase a scale since I didn’t have one at home. I’ve never been obsessed with my weight because I know regardless of what the scale says, it’s not a good indication of my health or fitness.
In this case however, a scale was necessary.
Our head coach Colleen Parsons taught us how to find out our sweat rate at a lecture on nutrition earlier this year. It’s as simple is this:
- Weigh yourself in kilograms naked and voided (so uh, go to the bathroom) before your run
- Then weigh yourself naked and voided after your workout
- Find the difference between your weights
- Every 1 KG of weight lost = 1 litre of water. To properly rehydrate, you need to consume 150-200% of the number of litres that you lost to account for how much water will run right through you and not be absorbed by your body
You don’t need to drink that water all at once but over the next few hours following your workout, it should be your goal.
I tracked my sweat rate for my two solo runs this week:
Wednesday, Sept. 23 – I did a 55-minute tempo run (fairly high-intensity)
- Before weight – 57.1 KG
- After weight – 56.2 KG
- 0.9 KG difference = 900 ML of water
- I estimated I should drink at least a litre and a half of water over the next few hours
Thursday, Sept 24 – I did a 45-minute low-intensity run
- Before weight – 56.8 KG
- After weight – 56.3 KG
- 0.5 KG difference = 500 ML of water
- I estimated I should drink about one litre of water
I suspect these numbers would have been vastly different in the summer when it was warmer or at the start of my training when I was in much worse shape. Continually taking a measure of your sweat rate will probably help you gauge how much water you need to drink to rehydrate on any given day.
P.S. I forgot to turn my scale to kilograms so in the photo you see my weight in pounds. I just converted it to kilograms after.