The heart recovers after a marathon

The question of whether extreme bouts of exercise like marathons do more damage than good to the heart always sparks discussion, thanks to occasional sudden deaths at sporting events (see this Jockology column for a discussion of the issue). Over the past few years, several research papers have found evidence that the heart does sustain damage during prolonged hard exercise – but these indicators are very hard to interpret. For more, see Alex Hutchinson’s Science of Running Blog.