'He maintained himself, he had some power in him, through which he could regulate his own fluids and has been able to maintain his balance,' Trehan, who monitored Hazare's health during the agitation, said Sunday.
The doctor said that medical science could not explain everything but Hazare himself managed his fast for all these days.
'Medical science may not fully understand but it is 'brahmachari shakti' and truly he has managed to live on his own reserves and paid a price for it. He lost seven-and-a- half kg,' the doctor said.
The 74-year-old activist's fast, during which he only consumed water and yet maintained high energy levels, has left many surprised.
Trehan also said he was surprised to see the activist fine even after fasting for 12 days. 'We are surprised to see a man in such a condition even after he has not been eating since Aug 16...can't say when he can start eating. It will at least take three days, it seems,' he added.
A recent fast by yoga guru Baba Ramdev saw his condition deteriorate, forcing him to take honey and lemon juice from the sixth day.
Ramdev started his fast June 4 and he started taking honey and lemon from June 9. He had to be administered a drip after seven days of the fast and was asked to break his fast June 12.
Hazare was, however, only having water, yet he looked healthy and interacted with the supporters almost everyday.
His 288-hour fast however didn't leave him unaffected, his heart beat was above normal, the principal doctor attending on him said Sunday.
'The heart rate is 94 which is more than normal (around 80). He is very dehydrated and exhausted,' said Trehan, giving the heath update of the activist.
Admitted to Medanta Medicity, Gurgaon, after he ended his fast against corruption, Hazare was being given coconut water and honey at regular intervals. Doctors said he would be given solid food later.
'He is being given coconut water and honey as he can easily absorb it. However, this would be increased slowly and gradually in a manner that his body can tolerate it,' said Trehan.