I did the ET with Matt 6 - 7 years ago we both enjoyed it and Matt found it to be a doddle, in fact I was told to stop Matt pulling a couple of times or we would be disqualified If I remember correctly there is a vet in attendance who checks the dogs temp & heart rate before they start and at the beginning and end of each rest break. Matt's HR at start of ET was 90 bpm and at end of ET 88 bpm ;)