Yesterday I finished an anual bike race - 100km of cross-country riding with 6000m total elevation that many amateurs (over 2000) around here attempt. For most people it takes between 5 and 12 hours ...
I'm running a marathon in March (my 5th overall) and the last marathon I suffered with severe cramp after 23 miles. I've been advised to take 'salt tablets' by another runner. I've done some research ...