Is young adulthood better characterized as a period of health-improving lifestyles or health-impairing lifestyles?

Is young adulthood better characterized as a period of health-improving lifestyles or health-impairing lifestyles? ... Young adulthood is a period of health-improving because this is an important time when peak physical performance is obtained between 19 and 26 years old.

Bacteria in the soil are also decomposers. Imagine what would happen if there were no decomposers. Wastes and the remains of dead organisms would pile up and the nutrients within the waste and dead organisms would not be released back into the ecosystem. ... Essentially, many organisms could not exist.