Muscle Matters - Paul Haslam

What you are experiencing is trouble with the law: the law of diminishing returns. Simply put, the same stimulus (workout) applied repeatedly over time will result in less and less results.

What you need to do is to start manipulating your exercises, sets and reps in a more planned fashion. Step one is to divide your training format into 12-week blocks, with each block containing new exercises for each body part. Step two is to divide the 12 weeks into three four-week cycles. Cycle one will see you perform 3-4 sets of 12-15 reps for each exercise. Cycle two will be 3-4 sets of 8-12 reps and cycle three will be 3-4 sets of 6-8 reps. This frequent change of stimulus will ensure consistent gains.