Wondering if anyone can help? Been doing a fair few long runs, 19/20 miles plus, no real problems at all with energy, stamina, legs or feet, etc, but towards the end of the run and particularly afterwards I seem to get bad indigestion / heartburn and feel really sick and can barely eat or drink anything for a while, even though at heart I am ravenous! I never ever suffer from indigestion in life generally. Am taking on enough water on the runs, especially as in this weather not that much is needed compared to in warmer conditions. The only thing I can think of that may be causing the indigestion is that I've taken either gels or carbo supplement powdered water (though not much in terms of quantity) along with water. Perhaps my stomach is reacting badly with the (admitedly small volume) of energy gel/liquid and giving me indigestion? Normally I don't eat or drink artificial stuff like this except when running long runs. Any help/advice much appreciated!