To be blunt, for the moderate amount of exercise the OP mentions you will need little more than a few sips of water to keep the mouth fresh and maybe a sweet treat afterwards – all these supplement regimes, recovery potions and release of toxins are just obscuring the issue.
OP did some exercise, gulped down 2 pints of water, ate dinner and felt a bit crap for a few hours – hardly merits discussion really
It might merit discussion for him. So why shouldn’t he discuss it on here, along with every other trivial matter under the sun that gets discussed ad nauseum.
The OP said he weighs 113kg, that’s 18 stone right? He mentions running 5k, he hasn’t mentioned his height. I consider myself reasonably fit, cycle 100 miles a week or so. I wouldn’t enjoy running 5k and I certainly wouldn’t enjoy doing it with 6 stone strapped to my back.