Garry Kasparov @Kasparov63
Depends on the competition and how hard & long you think! Competitive players burn so many calories playing chess, not casual players. Not due to skill level, but difference in intensity & duration. The adrenaline of tournament play is a big factor. Heart rate goes way up. — PolitiTweet.org
Steve Koczela @skoczela
@Kasparov63 How many hours of online chess do I have to play to avoid working out entirely?