One of Leonardo da Vinci’s secrets was hidden in special sleep scheme: he slept 15 minutes every four hours; this way he cut his daily sleep time from 8 to 1.5 hours. Due to this scheme he saved 75 percent of his sleep and, hence, extended his life time from 70 years all the way up to 100. Nicola Tesla slept for 2 hours a day, starting from age 19, and had enough time to do a lot during his life. By far not everyone can handle such schedule for long. Full story

Turning around in bed for the whole night, falling asleep right before the sunrise, waking up not well-rested, but rather exhausted. Sounds familiar? Insomnia can be a symptom of many different illnesses, but a healthy person can experience it as well. Insomnia mostly develops due to disturbed falling asleep in the evening, early wake-up time in the morning, or not deep enough sleep at night. A relatively healthy person can get insomnia due to a nervous over excitement, stress, or prolonged high physical activity. Full story