You can work longer with less pain and tension in the body
Insofar as the water supports the body weight, injured people, who suffer from obesity, or in an advanced age, can swim for prolonged periods without the voltage applied to the joints and bones. Moreover, swimming is one of the few sports that does not cause stress to the skeletal system.
To be in a swimming pool, it is less likely to make contact with hard surfaces that can create tension in the body, because the movements are cushioned by a water barrier. Better yet, swim in a heated pool, the heat causes loosen joints and muscles, which help prevent injuries during training.