I've found that during my recent lunchtime runs I've urgently needed to go "Big Toilet" after a few miles. Not sure if it's because I've eaten something different, or drunk more water, or that I'm going faster than on long slow runs, but it's a bit embarrassing and awkward. Fortunately I've always just about managed to hold on until I get back to work (probably more info than needed).

Doesn't seem to affect me at any other time though. Morning and evening runs are fine. How queer.

I bet the gardners round there love  you-some more fresh manure regularly.

This topic reminds me of an embarrasing/hilarious (depending on your viewpoint) experience a friend of mine once had, which I won't go into too much detail about in case someone is eating their dinner... but it's taught me the value of always wearing dark-coloured shorts. :-)

Anyway.

It does depend a lot on what time of day you run - usually I try and go first thing. If it's a long run (up to around 15miles), I'll usually have a big dinner the night before, then in the morning have a couple of strong coffees to make me 'go' before I set out. If it's 15 miles or more, I'll eat some quinoa mixed with peanut butter 3 hours earlier for a good mix of carb and protein. As the guys have said - a lot of it is down to trial and error.

Caffine powder Lucozade has the same effect for me. Race days always bowl of porage 2 to 3 hours before start for morning races, afternoon races is usually 3 rounds of cheese on toast, on both occasions sipping water only with a cup of coffee an hour before start.

I'm gonna try barley sugar twists just before the race for a bit of a sugar rush.

Although thinking about it I had a giant chocolate muffin with coffee last year half hour before a 10k trail race and got my PB when it was only going to be a tune up run for the half marathon that was 2 weeks away (hence why I broke the no food for 2 hour rule).