Current world chess champ:
People with good genes and good upbringing have a much better chance at being successful.
That means not only brains, but good bodies, emotionally stable, socially adjusted, etc etc.
I think most top chess players are married, and none are e.g. fat.
That aside, it's hard to do well in a game that can last many hours if you aren't reasonably fit. That doesn't necessarily mean you have to be athletic, but being frail or obese to an unhealthy degree is definitely a disadvantage.
Magnus chest is horrible and his shoulders are missing some muscle mass. However he is actually pretty good and football and seems "fit" compared to other GMs.
In my opinion most GMs are missing some muscle mass/size however Ananad supposedly goes to the gym.
I started going to the gym at 13 cause my left hand was way stronger than my right one, and I wanted to balance that cause I looked like a weird one-armed jacked dude.
I found hot chicks there (good motivation and free tacos de ojo, LOL, JUNTO CON PAJAS MENTALES)and some of my "buds" introduced me to anabolic steroids.
So I would say Im pretty fit, however I am at risk of heart attack according to my doctor.
Yes it does. I find that when I carb up, take my testosterone and bump my biceps I am a beast on chess.
Seriously tho, it does help being fit, you have more stamina, no wonder why good chess players are called grinders.
No at least not the really good players who take care of themselves and prepare for tournaments and take it seriously :)
Younger Kasparov circa 1980s was built like a rock when he showed up to tournaments he was always in fantastic shape and prepared Bobby Fischer use to box played tennis and went swimming and he did exercises in front of his TV (see the 60 minute episode on you tube) Steinitz would insist on doing his exercises he realized the importance as he aged of keeping in good shape.
Being athletic is no guarantee of success fat guy can easily blow athletic guy right off the board with a torpedo if he's a better player and has more experience but in an even contest with nerves extreme stress and real pressure that goes on for 4-6 hours athletic guy will outlast fat guy because he has more energy and the gas to keep going.
He has the edge in endurance it's like running a marathon or a 15 round fight in boxing how much have you got and how bad do you want it?
What media is reporting that all chess players are unathletic? Odd reporting. It seems you answered your own question in the OP.
I bet it's about 50/50.
Both Spassky and Fischer played tennis. Nearly every gm suggests that being physically fit is a must to be a top chess player. But if one has little atheletic ability chess might be a good hobby for them.
I'm 59, play chess a lot, and have climbed a dozen 14,000 foot (4,267.2 meter) peaks and completed a 15.4 mile hike across a mountain chain two weeks ago, so I wouldn't generalize about chess players.
So, are you unathletic? are chess players as stereotypical as the media says?