Lengthened partials, trend or powerful tool for muscle growth?

Lengthened partials have been shown in studies to be better than shortened partials or even full ROM for muscle growth. Lately lengthened partials have been exploding in popularity among the science-based crowd in hypertrophy training. Now there are entire workouts based solely on the lengthened partial, new exercises, people are creating different methodologies just to bias this new tool. However, is this just a fad, or is there practical evidence and examples of other bodybuilders using this to achieve success? That is the question that will be answered in this article.

A lengthened partial is a part of the exercise where the muscle is the most stretched out. Lengthened partial – lengthened and stretched muscle, shortened partial – shortened and squeezed muscle. In other words, the initial range of motion. To put it in context, an end of range of motion partial would be the squeezing part of the exercise, while a full ROM (range of motion) is including both of those as well as the middle ROM. Theory-wise, the muscle has to generate the most force to contract against resistance in the lengthened range of motion, which is most likely what is causing this relative increase in muscle growth. Studies have shown ¹, that either varying full ROM and lengthened partials, or going all in on lengthened partials results in more growth than other ranges of motion.

Tom Platz, known as “The Quadfather,” is a legendary bodybuilder renowned for his extraordinary leg development and intense training techniques. One of the best examples of the lengthened part of the movement being effective. Despite mostly training in the full ROM, Tom Platz specifically emphasized the deep stretch position of the squat, hack squat and knee extensions. Keeping an upright torso during the squat to specifically target the quads, letting the knees go forward in order to further stretch them out. Ofcourse, one of the biggest reasons his legs grew so much was the intensity he trained with, however his technique definitely played a part. While this is a good argument of full ROM being the best, it also shows how growth-inducing the fully lengthened part of the ROM is.

Dorian Yates, a six-time Mr. Olympia winner, renowned for his extreme intensity. Mostly used full range of motion, then all sorts of partials to finish off. His most exceptionally developed body part was his back, packing incredibly dense and defined lats. One of the most famous lifts he would perform was the Yates row, which emphasizes those same lats, and would later be used by Kevin Levrone, another legendary bodybuilder. It’s a variation of the barbell row where you’re more upright, essentially turning it into a partial range of motion. With this variation you’re able to use more load, therefore putting more weight on the lengthened position of the movement, with much less emphasis on the squeeze, as a more upright torso doesn’t allow you to bring the bar as high to squeeze your scapula. Another example of the lengthened position of a movement being a great tool for growth. He also used partials as a high intensity technique.

Despite the lengthened range of motion not being the main factor in their training (ridiculously high intensity was the main factor), it definitely played a role in building their strengths as bodybuilders. Used as a tool and not the entire system, it is very effective.

Based on the science and general consensus among the bodybuilding space at this moment, lengthened partials probably shouldn’t be used as a main training method. Most people recommend to wait until more research comes out for that. At this moment, it is recommended to use full ROM generally, and lengthened partials to finish off the movement. When performing full ROM you can also put less energy into the contracted position, rather focusing more on stretching out the muscle with each reppetition.

The best place to use lengthened partials is once you’ve finished a set, as a high intensity technique. That way you get the benefits of full ROM and the lengthened partial, while also increasing intensity massively. This forces you to use a weight you can actually handle and perform the lengthened partial technique safely. It also limits the amount of fatigue and muscle damage you can cause with this technique, as lengthened partials are inherently much more fatiguing and damaging for the muscle than a shortened partial.

Based on the current scientific studies and the way accomplished bodybuilders trained, the lengthened partial has always been a great hypertrophy tool. Best used as a finisher after one of your final sets of an exercise, it has its place in your training. The lengthened part of the full range of motion however has been shown to be incredibly hypertrophic and even the key to many bodybuilders physiques. From this you can also interpret, that only doing the partial can also be effective, however to know for sure we need more research to be done. To conclude, it is not a fad, simply becoming popular again due to new scientific studies. It is a great tool to increase your rate of muscle growth and burst through platoes.

1. https://pubmed.ncbi.nlm.nih.gov/33977835/
   https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6977096/ ↩︎