Without progression, the body has no reason to adapt and that leads to stagnant training. Which is known as the dreaded PLEATEU."If you keep on doing what you've always done, you'll keep on getting what you've always got." -- W. L. BatemanA common belief is that if you just stick with the program, results are inevitable.

Think about this...

If you aren't seeing results on a MONTHLY basis in some capacity, it's time to change the training protocol.

99% of success comes from having a well formulated plan. A good plan includes tracking your progress. By monitoring your nutrition, body composition, and keeping a training journal, you will be able to see how you are progressing or if you are not making any progress. Keeping some type of journal will allow you to make educated decisions on when and if it's time to change your training load (the weight you are lifting).

Frankly...

If you do not set specific goals, and if you do not monitor the own progress toward those goals, then how can you assess if you are making progress?Your training program should always be focused on progression to meet your overall goals. This is where having a specific goal and timetable is important. You don't want to just training the same way for an extended period of time and hope for results.

But let me go back to the beginning of your question and let's find out if there is a simple way to figure out when to increase the weight you are using in your training program.

Graves and Baechle developed a dynamic formula to assess when progression is necessary called the 2-for-2 Rule. They said that "if you can successfully complete two or more repetitions in the last set in two consecutive workouts for any given exercise the load should be increased."

For example, 3 sets of 8 repetitions may be prescribed for a particular exercise. When you can complete 2 more repetitions (i.e. 10 reps) on the final set for 2 consecutive sessions the weight should be increased.

The International Sports and Science Association (ISSA) recommends a load increase of 2% to 5% percent for advanced trainees and 5% to 10% percent for new and intermediate trainees.

But first a warning: Advanced athletes who are beyond these guidelines will probably need to adjust the ranges as necessary where a beginner might not. The reason for this is the beginner has much more room from improvement than a seasoned athlete.

Another reason for this is that a beginner has a lot of neural transformations occurring rather than muscle hypertrophy. Improved motor unit synchronization and the recruitment of new motor units account for this faster rate of progression. This is one reason that new strength athletes will progress in strength faster than muscle size.