Cnidaria (/naÉªËdÉÉriÉ/[4]) is a phylum containing over 10,000[5] species of animals found exclusively in aquatic (freshwater and marine) environments: they are predominantly marine species. Their distinguishing feature is cnidocytes, specialized cells that they use mainly for capturing prey.
Exercise Science is a multifaceted field of study in which movement or physical activity is the intellectual focus. This includes exercise of improvement of health and physical fitness and activities of daily living, work, sport, and play.
In many studies covering a wide range of issues, researchers have focused on exercise, as well as on the more broadly defined concept of physical activity. Exercise is a form of physical activity that is planned, structured, repetitive, and performed with the goal of improving health or fitness. So, although all exercise is physical activity, not all physical activity is exercise.