This is an article written by RICKIE HATHAWAY – BuyBulkWhey.com In the Field Correspondent.

No matter what kind of machine you get you’ll need some sort of resistance. Resistance comes in many forms ranging from steel to big rubber bands. How to choose is up to you.

Free weights come in many materials and are very versatile as they aren’t anchored down and are easily adjustable weight wise. Some free weights are made of steel and come in many weight values ranging from three quarters of a pound to a hundred pounds or more but can cost a very pretty penny. Vinyl weights are very cheap and durable however they don’t come in very large sizes. Concrete weights are basically concrete with a plastic coating and are very cheap but the concrete tends to crack easily. Some free weights are even made from lead but these can be expensive and hard to find.

Resistance bands are basically big rubber bands that you have to use your strength to stretch. They usually don’t have a lot of adjustments and wear out over time but are the most versatile resistance you can have while in their prime and are usually moderate in price.

Weight stacks are a group of weights stacked on a pole and rigged to a pulley. These can be adjusted to lift more or less weight very quick by moving an elongated bolt up and down. These sorts of weights don’t really have a lot of room for movement so your excursuses are limited to whatever the pulley is rigged to and these can cost a decent bit of money but it’s hard to lose something like this but please note the pulleys can break.

http://exercise.about.com/cs/exerciseworkouts/a/resistance.htm
www.nextag.com/weight-stack/stores-html
http://www.ruf.rice.edu/~ricerec/fitness/rice_fitness_center/free_machine.html