The weights should not be too heavy, too light. The weights are too heavy if you cannot complete the workout, and they are too light if you breeze through the workout too easily. Record your progress and review your diary to help make adjustments. Your diary will be the best tool you have to understand your improvements and lack of improvements. Remember the importance of form in your strength training program.
Form can be the difference between results and no results.
Proper form will help prevent strength training injuries and help develop balance, coordination, and flexibility. Progression Strive for progression with each strength training session weekly. If your program calls for 8-12 repetitions, then anytime you can do more than 12 repetitions, increase your weight.