I weigh myself every morning in the buff and after "ablutions" and have noticed that my weight varies by up to 2kg over quite short periods. e.g. 75kg one morning, upto 76.8kg another. I understand that hydration plays a large role in it but I consider myself well hydrated as I drink 2-3l of drinks per day, tea, milk, water, and am never dehydrated as such. I fact, after runs I'm never massively thirsty (even after a long one). I'm a creature of 'habit" so the morning weigh-in is post "paperwork" so to speak. What can cause such wide variation? I understand the sheer mass of a couple of meals can add up and also that glycogen depletion in muscles after extended exercise can reduce your weight and conversely see increased weight as glycogen reserves are replenished after a run, but can these aspects add up to 2kg difference (2.5-3% variation in weight)?
Could it be that a 75kg weigh-in coincides with a day's long runs glycogen depletion, lighter (mass) meals than usual and maybe a touch of dehydration? And the converse after a rest day(s) better hydration and higher mass meals?
The difference just seems a lot (and from memory my weight prior to taking up running was always much more stable with only 0.5kg variation at most.)
Anyone else have large weight swings? What's the experience of this of us who have trained for HM and M distances? Is glycogen depletion/replacement part if it? I found this article about it which suggests 100g glycogen stored in muscles and 400g in the liver (plus bound water to the molecules) = coincidentally 2kg.
(Warning - photo of cheese toasty included in article)
My longest run is only 12km to date and total weekly distance 20-30km - so surely not enough exercise to deplete glycogen reserves?