Serious runners are a whole other thing to a casual runner. I did a 20-30k per week for a decade without problems. When I doubled that - which required a very

Serious runners are a whole other thing to a casual runner. I did a 20-30k per week for a decade without problems. When I doubled that - which required a very intentional effort on my part - and ended up with injuries. But was able to address the underlying issues without too much drama.