The 12,000 word study letter, revealed 'he (Singh) shunned opportunities' to take a break.
According to Sanjay Baru, former media adviser, the Prime Minister had very little interest in relaxation and recalled a incident during Singh's official visit to Goa.
"I said to him, 'sir, it"s a weekend. Why don"t we stay Saturday night, spend Sunday morning on the beach and come back Sunday evening. You don"t miss a working day'.
"You know what he asked? 'But what do I do there?'
"Only Manmohan Singh could ask what he could do in Goa," Baru said.
Daman Singh, daughter of Manmohan Singh recalled that her father had taken only one vacation in the past 40 years after the family planned to go to Nainital, a hill station.
"As children we just assumed that"s the way all fathers are. He hasn"t changed at all," said Daman, a author, who is currently working on a book about her parents.
The report further called Singh the architect of India's economic liberalisation, who struck to his old austere habits and shunned expensive suits, fancy restaurants and luxurious cars.