We Strive For Fitness Failure: The Overload Principle

What is the “Overload Principle?”

It is the most misunderstood principle of working out.  SportsMedicine.com explains it the following way:  "The principle of overload states that a greater than normal stress or load on the body is required for training adaptation to take place. The body will adapt to this stimulus."

What does this mean?  

Every time you lift weights or load, upon completion of each set of lifts, you MUST achieve Momentary Muscle Failure (cannot lift the load anymore). For example, if you are training for pure strength gains, your rep range typically will be 1-5 repetitions or reps. You MUST NOT be able to lift the load 6 times.  

If you "fail" at 1-5 reps, you achieved Momentary Muscle Failure and applied the "overload principle."

When you do not overload the muscle to exhaustion (the ability to lift the load more than 6 times), your body will NOT adapt or improve towards your desired goals. Even if you only lift the load 5 times but still have the ability to lift the load 1 more time, you have not overloaded the muscle. 

When you bicep curl a load, say a pencil, you utilize only a percentage of muscle fiber for the contraction. Each time you lift the pencil, you will recruit a little more muscle fiber. Due to the pencil weighing so little, you will achieve little to no benefit to curling such a light load. You experience the same outcome if you lift a weight that does not challenge the muscle to muscle failure.

When you lift a heavier load, say 20lbs for the bicep curl, you will recruit more bicep muscle fiber on every repetition. As you perform each repetition, it becomes harder and harder to curl the weight and your bicep is recruiting more muscle fiber.

Finally at rep 4, you need assistance to lift the final repetition to achieve the 5 reps. Your bicep has recruited all of the muscle fiber it can recruit and is unable to lift the load/weight. If you did not have the assistance, you would not be able to achieve the 5 rep goal.


You have now achieved Momentary Muscle Failure and are utilizing the "Overload Principle." Muscle failure is critical in causing the adaptation to occur. If you do not utilize the "Overload Principle," you will be unable to achieve your strength, hypertrophy, power, or endurance goals you desire.

Written by Steven Zahn