As a coach, I think one of my responsibilities is to remind my athletes that they should fundamentally enjoy what they are doing and find value in their sport practice intrinsically: in other words, it's worth doing because the individual says it's worth doing.
Competitive weightlifting and running are tough sports and if you don't fundamentally get value out of it, the day-in-day-out grind of training (the "ditch digging" as I call it) will quickly sort out the wannabes from the gonnabes. To be really good at something you need a fair amount of mental toughness and resilience.
The last few years there has been a cascade of book and articles on mental toughness and persistence, or "Grit". Google scholar gets about 146,000 returns on the topic of Grit and Performance. Some like this. Who knew?
However, my contrarian side takes an automatic dislike to fads, and "Grit" strikes me as another candidate for the pop-psych/self-help Stuart Smalley section of you local Barnes and Noble; the latest flavor of the debunked 10,000 hour rule.
So I was amused and delighted by this article, in the Harvard Business Review which cites several academic studies on the downsides of Grit. The takeaway being, if your dedication and persistence to accomplishing a goal is damaging your life in some way, you should probably consider quitting and doing something else.