Regularity of sleep is an important factor for longevity, say researchers. Sleeping at the same time every day is important, in addition to getting about 7 hours of sleep or 7-9 hours, and feeling rested. Avoiding interruptions in sleep and napping are also important for longevity. Lack of social connectedness affects sleep. Starting early in life with good sleep habits helps in achieving a long healthy life. Other studies in Japan on good sleep habits have confirmed its importance for health and longevity.