The pulmonary vein sends the oxygen-rich blood back to the heart, according to NLM. The systemic circulation is the portion of the circulatory system is the network of veins, arteries and blood vessels that transports blood from heart, services the body's cells and then re-enters the heart, the Mayo Clinic noted.he systemic circulation is the portion of the circulatory system is the network of veins, arteries and blood vessels that transports blood from heart, services the body's cells and then re-enters the heart, the Mayo Clinic noted.
Fitness trainers and instructors lead, instruct, and motivate individuals or groups in exercise activities, including cardiovascular exercise (exercises for the heart and blood system), strength training, and stretching.They work with people of all ages and skill levels.roup fitness instructors organize and lead group exercise sessions, which can include aerobic exercise, stretching, muscle conditioning, or meditation. Some classes are set to music. In these classes, instructors may select the music and choreograph an exercise sequence.
The education and training required for fitness trainers and instructors varies by type of specialty, and employers prefer to hire those with certification. Pay The median annual wage for fitness trainers and instructors was $38,160 in May 2016. The median wage is the wage at which half the workers in an occupation earned more than that amount and half earned less. The lowest 10 percent earned less than $19,150, and the highest 10 percent earned more than $72,980.