If you want to build strength, you’ve got to tax your muscles, connective tissue, and bones. Incrementally challenging yourself in the weight room is the most important stimulus for building muscle and strength.
Lifting the same amount of weight, every workout, won’t make you stronger. It’s necessary to gradually increase your loads, as you progress, in order to strengthen your muscles and prepare them to handle heavier weights, over time.
You shouldn’t be able to complete the last few repetitions of your final set as easily as the first few reps. It should be difficult to finish those last few reps, while maintaining good form and technique.
As you adapt to the training load and repetitions, it’s important to have a progression strategy. Advancing exercise loads ensures that improvements will continue over time. It’s also important for you to keep track of your progress and chart each workout.
A conservative method that can be used to increase your training load is called the 2-for-2 rule. If you can perform two or more repetitions over your assigned repetition goal in the last set in two consecutive workouts for a certain exercise, weight should be added to that exercise for the next training session. (Baechle, T. and Earle, R.; Essentials of Strength Training and Conditioning)
The quantity of load increases, when progression is warranted, should generally be about 2.5-10%.
Get STRONGER, Get FASTER!