How much resistance should I use in my strength training program?

The amount of sets you should perform per workout for your resistance training exercises depends on what goal you are trying to achieve and your level of resistance training experience. For example, to improve endurance it is recommended to perform 1-3 sets per exercise per workout; to improve strength it is recommended to perform 2-6 sets per exercise per workout; and to improve power it is recommended to perform 3-6 sets per exercise per workout. Regardless of the desired goal, it has been suggested that to prevent overtraining, no more than 24 to 36 total sets should be performed per workout; however, for a beginner to resistance training this number may be as low as 5-12 total sets.

You can estimate the amount of weight you will need for a particular rep range if you know the intensity level you want and your one repetition maximum (1RM). 1RM is defined as the most amount of weight you can lift only one time. For example, if you want to lift a weight 8 times, your 1RM is 100 pounds, and you want to workout at 100% intensity, you should lift 80 pounds. If you want to lift the weight 8 times at 70% intensity, you should lift 56 pounds.

The safest way to calculate 1RM is to pick a weight you think you can lift 5 to 10 times and then, with the help of a spotter, see how many times you can lift that weight until failure. You can then plug those two numbers, weight lifted and repetitions performed, into a formula to estimate 1RM. One common formula for estimating 1RM is [(R/30) + 1] x W. This means if you can lift 150 pounds 6 times, your estimated 1RM is [(6/30) + 1] x 150 = 180 pounds.

For a list of formulas used to calculate 1RM, please see http://en.wikipedia.org/wiki/One_rep_maximum.