Sarah is interested in purchasing a piece of home exercise equipment for aerobic workouts.She wants to build her cardiorespiratory fitness but has knee problems.Which of the following would be the best option for her?

A) an elliptical trainer
B) a motorized treadmill
C) an "all-in-one" weight machine
D) a stair-climbing machine

Cardiorespiratory Fitness

The capacity of the heart, lungs, and circulatory system to provide oxygenated blood to muscles in action throughout extended periods of physical exercise.

Elliptical Trainer

A stationary exercise machine used to simulate stair climbing, walking, or running without causing excessive pressure to the joints.

Aerobic Workouts

Exercise activities that increase the heart rate and promote the circulation of oxygen through the blood and are performed over extended periods.