Stan Wawrinka has opened up on how he ran himself into the ground to cope with the panic attack he suffered moments before the US Open final.

The Swiss came from a set down to beat Novak Djokovic at Flushing Meadows and claim his third grand slam singles title last month.

But the 31-year-old was in tears after being overcome with anxiety shortly before stepping on court at Arthur Ashe Stadium, prompting him to instigate the only coping strategy at his disposal in the cauldron of a slam decider. 

"I was close to breaking point - the moment where you let it all out, physically and nervously," he wrote in Swiss newspaper Le Matin Dimanche.

"So, how did I do it? I'll tell you. I hurt myself. 

"I tried to extend rallies as much as possible - one more shot, and another - to make the legs churn and not the head. I pushed myself until I ran out of breath. 

"Past that point the mind isn't too capable of thinking.

"When I'm nervous like that, the fatigue feels a lot, lot stronger.

"And my legs hurt so much. I even screamed at my box, 'I can't make it. I'm dead. My legs are gone'.

"I was hurting so much. I was pushing myself so hard. I was so out of breath that I finally ended up muffling those little voices in my head.

"With the fatigue I was no longer thinking about those voices and I even started to play well, to let a few shots go with the backhand and on serve."

Wawrinka withdrew from this week's Japan Open Tennis Championships as he continues to deal with the effects of his physical and mental exertions in New York.

"Now, I have to relax the machine a bit," he said.

"When you win a grand slam you reach an insane level of emotion, you enter another "state" … and it's sometimes difficult to recover from it."