Which of the following is an advantage of swimming related to fitness?

Swimming is widely recognized for its various fitness benefits, with one prominent advantage being its ability to improve flexibility. The range of motion required during swimming strokes encourages the stretching of muscles and joints. As swimmers move through the water, they regularly engage their arms, legs, and core in various positions, which helps promote flexibility throughout the body.

This improvement in flexibility is crucial not only for swimming performance but also for overall physical health, as it can enhance muscle elasticity, reduce the risk of injuries, and contribute to better posture. Swimming can thus serve as an excellent low-impact workout that concurrently builds strength and enhances flexibility without putting excessive strain on the body.

The other options do not accurately reflect the benefits of swimming in the context of fitness; for example, swimming does not inherently reduce the need for outdoor exercise, assist with weight gain, or increase reliance on machines, as it is fundamentally a natural and dynamic form of physical activity.