During the early 1940s, Mahan said "
Thoongamal Thoongi Sugam Peruvathu Ekalammo" (a sleep without sleeping to gain ultimate pleasure) but in the 80's after much analysis
Mahan advised everyone to get their normal sleep of 8 hours and
continue with normal meditation of up to 30 minutes or so 2 or 3 times a
day because if everyone don't sleep in the night and only do meditation
the marital life will be affected and cause much domestic problems. The
above statement was mentioned in the early days in a fit of fiery
enthusiasm and was downplayed after some practical
experiences.