There are many sophisticated exercise bikes on the market. Air bikes are more than capable of giving you a tough cardio workout. The ProForm XP Whirlwind 320 Exercise Bike is such a bike. It features air resistance, so the faster you pedal, the harder your workout gets. You get 14 workouts and can connect your music player to listen to your favorite tunes while exercising.
The machine has 250 lbs. weight capacity and a heart rate monitor. Its wheels let you move the bike around easily. Sets you back under $282.