Yes. Certainly when we look at our own lives and sadhana, we know this. Apart from a sense of self-disgust, the energy lost is enormous. One can feel it streaming out, especially from the root or muladhara chakra. Swami Narayananda, a disciple of Mahapurush (himself a flawless exemplar of continence) is a good authority and goes into some detail in his books as to the importance of Brahmacharya "in thought, word and deed". If not always attainable it must surely be the ideal for all sincere aspirants.
Dear anon, apologies for delay. Have limited internet access at present. Perhaps the best Swami Narayanananda book, (or my personal favourite) is "The Way to Peace, Power and Long Life" - ISBN 87-87571-59-5. My copy is twenty years old, however, and may now be out of print. Here are the addresses of the Indian Math : Sri Narayanananda Math, RA/ 55, Inderpuri, New Delhi 12, INDIA., and the U.S : N.U Yoga Center, 1418 N. Kedzie Ave. Chicago, Ill. 60651 USA. Two other titles you may be interested in are "Brahmacharya, its necessity and practice for boys and girls" and the more straightforward "Sex-sublimation". All the best !
