I am excited about bike riding and was happy to get my new bike (pictured below):

It is a hybrid (comfort/mountain bike) 2006 GT Timberline Comfort Mountain bike. I am totally happy with it and I've already put some miles on it. The summer is a great time to get outdoors and bicycling for fitness is a fun way to burn calories. If you're new to bike riding there are three main types of bikes that you may want to consider for a good workout.
Road Bicycle - These types of bicycles are also referred to as "racing bikes." They are meant to be rode on paved areas and are built for speed. They are made to be lightweight and aerodynamic. This is the type of bicycle you would see someone like Lance Armstrong use.
Mountain Bike - These bikes are made for riding on dirt trails or rugged terrain. They are much more sturdy than a road bicycle. They have chunky tires (knobby tires in bike terms) and many come with front and rear shocks. Mountain bikes are fun but are not very comfortable for riding around the neighborhood.
Hybrid Bicycle - The hybrid bike is my favorite type because you get the best of both worlds. It is a combination of a road bike for speed as well as a mountain bike for rugged terrain. They are much more comfortable for longer riding and for trekking around the neighborhood or riding bike paths. You can have your hybrid built to cater your tastes, meaning, it can be built closer to being a road bike or closer to a mountain bike.
Calories Burned Riding a Bike
The best part about having fun riding a bike is that you're staying fit and burning calories! So how many calories can you expect to burn? Below is simply an estimate but can serve as a guide to give you an idea of what your calorie burn is:
150lb person per 1 hour of riding:
Light effort - 380 calories
Moderate effort - 500 calories
Strenuous effort - 630 calories
Bike riding is a great cardiovascular workout and it's easy on your joints. If you are searching the market for a new or used bike, keep in mind the hybrids. They offer a much easier and comfortable ride.

{ 2 comments… read them below or add one }
Hybrid bikes are a great concept. The GT and Trek models in this style of bike are awesome. There comfortable riding off-road and you can cycle quicker on the road.
I agree, hybrids are awesome. They are very comfortable and still fun to ride.