Most of us believe that old age is as inevitable a biological process as the change of seasons. Over the years, human muscles weaken and contract, our body’s metabolism slows down, the skin loses its freshness, elasticity and wrinkles. For a long time, scientists believed that the aging process occurs evenly and begins in youth, at the age of 25. However, recent scientific research shows that people age sharply, in leaps and bounds, in two stages. The first occurs at the age of 44, the second – at the age of 60.

Has this ever happened to you? You go to bed one person – healthy and full of strength, and wake up a completely different person – feeling worn out, like an old man. We usually attribute such changes in health to the consequences of a severe viral infection or prolonged stress.

But sometimes there are no visible reasons for the deterioration of the condition: a person is not sick, his life is going smoothly, without problems, but his physical strength is rapidly decreasing. And this happens in certain age periods. Scientists from the United States, after a series of tests with volunteers, came to the conclusion that aging is not a slow and constant process.