From your third link:
"However, a number of competitive, but non-physical, activities claim recognition as mind sports. The International Olympic Committee (through ARISF) recognises both chess and bridge as bona fide sports, and SportAccord, the international sports federation association, recognises five non-physical sports: bridge, chess, draughts (checkers), Go and xiangqi,[4][5] and limits the number of mind games which can be admitted as sports.[1]"
"The precise definition of what separates a sport from other leisure activities varies between sources. The closest to an international agreement on a definition is provided by SportAccord, which is the association for all the largest international sports federations (including association football, athletics, cycling, tennis, equestrian sports, and more), and is therefore the de facto representative of international sport.
SportAccord uses the following criteria, determining that a sport should:[1]
- have an element of competition
- be in no way harmful to any living creature
- not rely on equipment provided by a single supplier (excluding proprietary games such as arena football)
- not rely on any "luck" element specifically designed into the sport.
They also recognise that sport can be primarily physical (such as rugby or athletics), primarily mind (such as chess or Go), predominantly motorised (such as Formula 1 or powerboating), primarily co-ordination (such as billiard sports), or primarily animal-supported (such as equestrian sport).[1]"
So it is mostly up for debate even if some people here think that only their definition can be correct and others are willfully wrong.
No, because Chess doesn't involve physical exertion.
[1]https://en.m.wikipedia.org/wiki/Athlete
[2]https://dictionary.cambridge.org/dictionary/english/athlete
[3]https://en.m.wikipedia.org/wiki/Sport
[4]https://dictionary.cambridge.org/dictionary/english/sport
not sure how you quantify physical exertion?
https://link.springer.com/article/10.1007/s00421-008-0908-2