Professional players work almost every day, for hours on end, and the emphasis is on the word 'work.' It can be with a partner or it can be alone, but professional chess is always a pursuit of something new and surprising.
Other quotes by Viswanathan Anand
I go to the gym every day. That tends to taper off when I'm at a tournament. During tournaments, I'm not trying to build fitness. I'm simply trying to keep away any kind of tension. I go for long walks to clear my head.
I don't bench press, but I use machines to work 10-12 muscle groups. Biceps, triceps, a few things for the back, calves, shoulders and so on - and then I'll go on the running machine, cross-trainer or mountain climber.
The broader the chess player you are, the easier it is to be competitive, and the same seems to be true of mathematics - if you can find links between different branches of mathematics, it can help you resolve problems. In both mathematics and chess, you study existing theory and use that to go forward.