Which of the following is NOT an effect of massage?

The correct choice reflects that reduced hydration levels are not an effect of massage therapy. Massage therapy is known to promote circulation, relieve tension, and enhance overall well-being, which can contribute to a person's optimal hydration status rather than decrease it. When tissues are manipulated through massage, the increased blood flow can aid in the distribution of nutrients and fluids throughout the body, which supports healthy hydration levels.

In contrast, the other options—such as increased flexibility, improved sleep quality, and decreased muscle soreness—are all well-documented benefits of massage. Stretching muscles during a massage can lead to greater flexibility, while relaxation techniques used during massage often contribute to better sleep quality. Additionally, massage alleviates tightness and promotes recovery, resulting in decreased muscle soreness.