Is swimming the best sport for our health?'Best' is very subjective. Different people have different definitions of 'best'.
Anyway, swimming is beneficial to your health. Swimming regularly may help reduce the risk of chronic illnesses in some people.  Swimming is also a relatively safe exercise. Swimming can support up to 90% of the body's weight in the water, so those who are overweight have disabilities or some injuries can take part without putting as much strain on their bodies.
However, swimming may not always be a convenient sport. For example, your swimming complex may be far away, or a lifeguard must always be present etc. Hence, running is an alternative. Running's benefits include improved cardiovascular hearth, lower blood pressure, lower cholesterol and higher metabolism. You can also get to experience 'runner's high'.
When you exercise, you have to have a goal. What do you want to achieve? Lose weight? Gain weight? Gain muscle? Personally, I go to the gym and use the free weights to gain muscle and strength. I go there 3 times a week. I have observed that my muscles are growing and that gives me the motivation to continue. So instead of finding out what sport is the 'best' for whatever. Find what your goal is and pursue it.
 Health and fitness benefits of swimming