Seven hours' sleep keeps older brains sharp | News - The Times

Eight hours of sleep has often been touted as the optimum amount but it appears that seven may be best for those in middle age and beyond to stay sharp, a stud

Eight hours of sleep has often been touted as the optimum amount but it appears that seven may be best for those in middle age and beyond to stay sharp, a study suggests. The research, which involve… [+529 chars]

full article...