The 20% Rule: When is it Time to Quit Your Lift?

Most of my clients truly want to achieve their goals as fast as possible. Because of their motivation, they are driven to push through workout fatigue. While perseverance is key for any successful program, is there a time when persevering can be detrimental for your gains? YES!

It's named the 20% Rule by Charles Poliquin, a world renown personal trainer. I will paraphrase what Charles said...

Overloading the muscles is key to achieving your goals. (Refer to We Strive For Fitness Failure). You know you are finished with an exercise when you have to reduce your load or reps by 20%.

Example 1:

Let's say you are bench pressing 8 sets of 100lbs for 10 repetitions. The first 3 sets, you complete the 10 reps with 100lbs. Set 4, you complete 9 repetitions of 100lbs. You have reduced your reps by 10%. Keep proceeding. You can either go 1 of 2 directions: either keep the same weight and let the reps decline or reduce the load to keep your 10 reps on track. Both options will keep you achieving your goals. However, we do need to pay attention once we cross the 20% threshold. Set 5, you keep the 100lbs load but only can do 8 reps. You should still keep working the bench press. Set 6, you can only perform 7 reps of 100lbs. You have crossed the 20% rule.

Charles explains at that point your CNS (Central Nervous System) is overloaded for that exercise and you should stop performing it for the remainder of the workout.

Example 2:

We will perform the same workout as above however we will reduce our workload a different way. Same numbers as above except on Set 5, you reduce your load to 90lbs but now you can lift the load for 10 reps. You have still reduced the load by 10% despite keeping your repetitions at 10. Keep proceeding. Set 6, you lift 90lbs 9 times because you are just inside of the 20% rule, you can keep lifting. Set 7, you lift 90lbs 8 times. Again, you have crossed the 20% rule and are now done with the bench press.

While you crossed the 20% threshold for that lift, you can still complete the remainder of the workout. You could switch to a chest fly. For example, you had to stop lifting bench press at Set 6 but wanted to perform 8 sets. The final 2 sets you perform a chest fly instead. In example 2, you had to stop lifting at Set 7. You would perform 1 set with the chest fly.

Despite the overload in the nervous system from the bench press, you can still perform the final sets with an alternate exercise. Because you changed the movement, your nervous system will still be able to perform the movement safely and effectively. In addition, because of the change, you are still teaching the body how to persevere to become accustomed to lifting 8 sets.

What are you to do?

When you are lifting weights, push yourself hard. When you reduce your output (reps or load) over 20%, you are finished with that exercise. This does not mean you are to stop lifting. Simply move on to an alternate exercise for that body part.


Steven Zahn

ACE Certified Personal Trainer

NASM Certified Personal Trainer

Pre and Post Partum Certified

Dragondoor Publications: HKC Russian Kettlebell Certified