So you've committed to trying strength training. Good for you. But you don't want to buy a set of free weights or use those filthy ones at the gym. Understood. Resistance bands are a great option: cheap, lightweight, easy to put away and even pack, for those workout-filled vacations you're always taking. (Yes, that's a joke.)
But it can be hard to know which ones to use, right? Here's a quick to the colorful pile of pain-inducing spaghetti from toughest (most resistance, meaning you need the most strength to use it) to least resistance (meaning the easiest):
There are a few other colors too. Purple is also very hard (lots o' resistance), and orange bands can be as well, but the colors above tend to be the most common.
Which brands and colors to buy can take a little trial and error, and you generally will need two or three different resistances (colors) to start. For example, most people tend to have a little more strength in their biceps (the upper inner arm), even if they're out of shape, so they can go a little heavier with their resistance; women may start with green or red, while men can often start with blue or red for Biceps Curls.
Shoulders, on the other hand, can be quite weak, so you may need to start with a yellow or green cord at first. It's easy to progress when you get stronger: You just move on to the next level/color of cord.
You don't need to buy cords/bands online or at a sporting goods stores, either. Many discount stores like TJ Maxx have them in their exercise section (along with accessories like yoga mats, water bottles, iPhone/iPod armbands, and socks).
Many of the 25 exercises on ih8exercise.com feature some kind of weight/strength/resistance to help build muscle strength, but a number just use your body weight to do the same thing. Both are effective, as our free weights and the weight machines you see at the gym. It's all good when it comes to building strength.
Do you use resistance cords in your workout? What colors do you use? Is there a brand you prefer?