(HealthDayNews) -- Stationary bicycles offer a convenient, safe, low-impact cardiovascular workout.

When purchasing a stationary bike for home use, you need to consider two major factors -- seating position and method of resistance, says the American College of Sports Medicine.

For many people, an upright stationary bicycle is fine. But people with lower back pain or problems with mobility or balance may get a safer, more comfortable workout on a semi-recumbent stationary bicycle.

Stationary bicycles use different methods of resistance -- friction belts or wheels, magnets, hydraulics or fans.

Take time in the store to test-ride different kinds of stationary bikes, checking them for adjustability, noise, ease of operation and comfort.