In fact, all recommendations for water intake are very relative. It seems to me that everything is very individual. It all depends on weight, sweat rate,humidity, temperature, etc. In young people and athletes, when correcting water balance, I use urine color chart. In the elderly, when assessing the water balance, it is impossible to use the color of urine, the data of an external examination and BIA, since they are not indicative dehydration. Ideally, we should look at the osmolarity of the blood, which is difficult to do outside the hospital
However, controlling water balance is very important, especially for the elderly. In 2009, we conducted a prospective cohort study of a random sample of community-dwelling adults aged 65 and older. We found that those who drank more than 5 glasses of water a day had higher grip strength and lower all-cause mortality during the 5-year follow-up than those who drank 2 and less glasses of water per day. Unfortunately, we found no information on the distribution of water in the body