Weight Lifting (cont.)

How do I know how much weight to lift?

Trial and error is the way to determine how much weight to lift. Select a weight that looks close to what you think you can lift based on your goals. If general conditioning is your goal, then select a weight you think you can lift eight to 12 reps (or 12-15 reps for beginners). If you can lift it 25 times with ease, then it's too light, and if you can lift it only four times, then it's too heavy. There are no formulas to calculate this. Simply decide what your goal is so you know how many reps to lift, take a guess by looking at the weights, and then give it a try. You'll get good at this quickly.

How much do I increase?

Unlike aerobic conditioning where duration and intensity is increased by 10%, increases in the weight you lift aren't prescribed with such precision, partly because muscle groups vary so much in size and strength, and partly because of the practical matter of the weights available at the gym. Typically you increase to whatever dumbbell is next on the rack (or plate on a weight machine), and so if you're lifting 12 pounds with biceps curls, then the next dumbbell available is usually 15 pounds. There is an option to increase in smaller increments with dumbbells by using an accessory called a donut, a magnetic 1¼ pound weight that attaches to the end of the dumbbell (they come in other weights besides 1¼ pounds as well). Weight machines have half weights for the same purpose. Ask your gym manager to purchase donuts if they don't have them.

Free weights vs. machines

Dumbbells and barbells are free weights. They are "free," or untethered, unlike a weight machine where the weight stack is connected by cables to cams and pulleys and only move in one direction. There are advantages to both styles of lifting.

Weight machines:

1. Weight machines are easy to learn and use.

2. There are some exercises you can do with a machine that you can't do with a dumbbell. For instance, cable rows would be difficult to replicate with free weights. You could do bent over dumbbell rows, but they won't be quite the same. For my money, cable rows feel smoother than any exercise in the gym!

Free weights:

1. Free-weight training requires balance and coordination, and so if you are involved in a sport that requires balance, or you just need balance training, then free-weight training might be more effective.

2. Free-weight training may recruit more muscles than a machine because you have to stabilize your body when you lift a dumbbell, whereas the weight machine supports you. For example, a biceps curls is going to feel more natural and use more muscles in your torso (to support the weight) than if you did a seated biceps curl in a machine where the machine does some of the work and you can lean against it for leverage.

3. There are a variety of exercises that you can do with dumbbells that you can't do with machines. Lunges, step-ups, and many upper body exercises can be performed with free weights if you're creative.

4. There is no evidence to suggest that either method is superior to the other. My suggestion is to combine free weights and dumbbells to get the best of each. The ACSM weight training position stands states the following: "For novice to intermediate training, it is recommended that the resistance training program include free-weight and machine exercises. For advanced strength training, it is recommended that emphasis be placed on free-weight exercises, with machine exercises used to complement the program needs."

Source: MedicineNet.com
http://www.medicinenet.com/weight_lifting/article.htm