Accommodating resistance means you modify the weight behind an exercise such that the resistance curve of the exercise matches your body’s strength curve for that exercise. And it's important to know what both of those things mean, and how they relate in your weightlifting when you work with resistance training exercises.
What is Exercise Resistance Curve?
With many exercises, the actual amount of resistance varies at different points of the exercise. With a barbell curl for instance, you’re lifting the weight almost horizontally near the bottom and top, and straight up near the middle of the exercise — thus the resistance is highest at the midpoint of the exercise.
Compare that to a squat or bench press, where the resistance is about the same throughout the movement (since the weight goes straight up and down), at the same angle the whole way through.
This is the exercise's resistance curve — the degree of resistance the exercise provides at various points in the movement.
What is Your Strength Curve?
Muscles are strongest around the midpoint of their active range of motion. Your bicep and tricep, for instance, are at their strongest when your elbow is about half bent.
This is why the hardest part of the bench press is the bottom of the movement when the bar is on your chest: the weight is the same throughout, but you’re weakest at the bottom. Near the top, your pectoral muscle gets weaker again, but the shoulders and arms are more able to help than they were at the bottom.
By the same token, pull-ups and chin-ups are hardest near the top, because the involved muscles reach the ends of their range of motion. That’s why people can often get 80% of the way up fairly easily, yet not get their chin over the bar.
The strength curve refers to how strong your muscles are at various points during a movement.
Resistance Training Exercises: How to Make the Most of Them
So again, we want to match the strength curve to the resistance curve, such that the exercise is about equally difficult all throughout, and doesn’t have a particular “sticking point.” Accommodating resistance is a catch-all term for methods of doing this.
Research shows that applying accommodating resistance to an exercise produces significantly greater increases in strength and power compared to using normal, constant resistance. There are several ways to apply accommodating resistance to an exercise. First and foremost, you can use resistance bands.
Use Resistance Bands to Amplify Resistance Training Exercises
You can attach elastic bands to a weight. This is most commonly done with barbell bench presses and squats, using a pair of identical elastic bands, one attached to either end of the barbell. The lifting stretches the bands, causing the resistance to increase as the barbell goes up.
This video shows how to attach the bands for a bench press, and this video shows how to do it with squats. You can also use just a single band for the bench press, as shown in this video; that isn’t possible for squats though.
How to Calculate Weight + Bands
You should aim to replace 30–40% of the total weight with band resistance — so if you squat 155 pounds, you should use about 95 pounds plus bands that each add 25–30 pounds of resistance. The bands will list a range rather than a single number, i.e. 15-35 pounds. Base your calculations on the highest resistance they’ll provide.
How Bands + Lifting Can Actually Be Safer
As an added bonus, the use of bands makes squats and bench presses safer, since eliminating the sticking point means you’re not likely to get trapped under the bar. Note, however, that the bands do change the angle of the exercise, which means the muscles are worked in a slightly different way, and your technique has to adjust accordingly.
You can achieve the a similar effect by attaching chains to the ends of the barbell. As the barbell goes up, more of the chain will rise off the floor, adding weight.
Since chains are heavy, louder, and more expensive, they’re generally owned by the gym rather than the trainee. Chains are mostly good for competitive powerlifters; for the rest of us, the convenience of bands makes them a better option.
In short: by attaching resistance bands to a barbell and using that as part of your “weight,” you can build more strength and a more well-rounded physique while making the exercise safer.
John Fawkes is an NSCA certified personal trainer based in Los Angeles.