What can go wrong will go wrong

I don't know what else could have gone wrong this morning. I set off this morning for a fartlek session with my Garmin strapped to my wrist. I had just checked the battery status and it said it had quarter of a charge left. This did last very long as after the first half a mile it bleeped and switched itself off, as I was still in warm up and not that far from home I doubled back and got a new set of batteries.
New batteries fitted I duly set off again. I managed to get a further mile before my stomach started acting up, luckily I was fairly close to the local shopping centre and its conveniences!
OK nothing else can go wrong can it? Wrong, I finally managed to start my fartlek session and was happily doing all sort of distances when my HRM chest strap decided to slip down and no matter how many times it got put back it kept on coming down again. In the end it slipped down to my waist and stayed there till the the run was finished.
So a couple of lessons
1) Never believe the battery readout on a Garmin
2) Don't have red onion tart the evening before a morning run
3) Make sure your chest strap is on properly!