Final answer:
The treadmill is the appropriate piece of equipment for adding intensity to a lower body workout and can be set to an incline to help work the upper body.
Step-by-step explanation:
1) Treadmill is the piece of equipment that can be used to add intensity to the lower body, and placed on an incline to work the upper body.
The treadmill is versatile exercise equipment that allows for adjustments in speed and incline. Increasing the speed on a treadmill adds intensity to the lower body workout, engaging muscles like the glutes, quadriceps, hamstrings, and calves. Elevating the incline of the treadmill shifts the focus to the upper body to some extent, as it requires the use of muscles in the back, chest, shoulders, and arms to stabilize the body and maintain form. This means that the treadmill can offer a comprehensive workout by targeting different muscle groups based on the adjustment of the incline and speed.
The other pieces of equipment, such as the elliptical machine, stair climber, and rowing machine, also provide good workouts. However, they don't have the same functionality to specifically add an incline to target upper body muscles. The elliptical machine and stair climber focus more on a lower body workout, while the rowing machine targets both the upper body and lower body but in a seated position and without the incline feature.