Lengthened Partials: Exercises I Emphasize
Where and Why I Emphasize Lengthened Partials In My Current Training
Recently, I posted a deep dive into research on range-of-motion where I emphasized the value of the stretched portion of repetitions for increasing muscle growth. Specifically, I addressed the concept and benefits of lengthened partials, or essentially half-repetitions completed in that stretched portion of the movement.
In addition, I sat down for a podcast with a world expert in range-of-motion and using lengthened partials for increasing muscle mass and strength, Milo Wolf P.h.D. (check out the full conversation here).
Though both that deep dive and podcast discussion cover the research behind lengthened partials, I realize that I didn’t share much in terms of specifics of how I’m using this training tactic.
In this post, I’ll cover exactly which exercises I use lengthened partials for in particular, as well as why I emphasize using them for these specific exercises.
Taking Advantage of the “Shortened-Biased Resistance Curve”
One of the first things I noticed when implementing lengthened partials is that they are harder for some exercises and easier for others. Simply put, this is due to the physics of different angles of motion for different exercises and the mechanical relationships of different muscles and joints.
The important point is that some exercises are biased in the direction of loading the target muscle more in the lengthened half of the movement, others are biased towards loading the shortened half of the movement, and some fall somewhere in between.
One simple way to identify which bio-mechanical flavor a given exercise fits into is to determine whether using lengthened partials makes that exercise easier or harder than when using full range-of-motion.
If the lengthened partials are more difficult or similarly difficult to repetitions completed with full range-of-motion, then the exercise is probably more lengthened biased. On the contrary, if the lengthened partials are significantly easier to perform, then the exercise is probably more shortened biased.
In addition, you’ll find you’ll be able to use heavier weight or get more repetitions with the same weight when using lengthened partials as compared to full range-of-motion if the exercise is more shortened biased. For example, I can lift significantly more weight when using lengthened partials for hammer rows–a shortened biased exercise–than I can when using full range-of-motion.
So, who cares? Well, in theory, lengthened partials are potentially more impactful for exercises that are shortened biased, since these exercises miss out on the most load during the lengthened portion of the movement.
On the other hand, though lengthened partials are still useful for lengthened biased exercises, these exercises already put the muscle under high load in the stretched portion of the movement. For this reason, we may have less to gain from using lengthened partials for these already lengthened biased exercises than from using them for shortened biased exercises.
Another way to think about this is that you spend the most energy on the shortened portion of the movement when doing shortened biased exercises. So, by cutting that part of the range-of-motion out, you can allocate more load and energy towards the lengthened portion of the movement–which is the part that is likely most important for muscle growth. (I)
Some examples of these generally shortened biased exercises are many of those that target the back muscles, side deltoids, rear deltoids, biceps, and calves. (Dr. Wolf also touched on this during our conversation) And, these are the types of exercises that I have been heavily implementing lengthened partials with.
Specifically, in my recent training, it’s these ones:
Lateral Raises (cable lateral raises are especially useful for loading the lengthened portion of the movement)
Bicep curls (seated incline curls add even more load to the lengthened portion of the movement)
Calf-raises (using a leg press machine or standing on a step allows you to get a deeper stretch with these)
Again, I also implement lengthened partials with more lengthened biased exercises–like dumbbell bench press variations and squats–but I especially emphasize this technique with shortened biased exercises that offer greater returns when doing so–in theory.
Improving Mobility
In addition to exercises that theoretically benefit more from lengthened partials from a muscle growth perspective, I implement lengthened partials more commonly for movements in which I lack mobility.
Though I have not found any research on lengthened partials and mobility specifically, there is research suggesting that resistance training can improve range-of-motion as much as stretching or stretching AND resistance training. (II)
For more on this concept specifically, I covered research on mobility benefits from resistance training here.
And, this makes sense to me, in that resistance training to end ranges of motion essentially involves loaded stretching. In addition, it makes sense to me that lengthened partials may provide mobility benefits on top of those achieved with full range-of-motion, since the lengthened portion of the movement is when the muscle is being most stretched–a point that Dr. Wolf brought up during our conversation.
Even if this hypothesis is wrong, I don’t think I’m sacrificing any mobility benefits by using lengthened partials as compared to full range-of-motion–making lengthened partials a low-risk choice from a mobility standpoint.
One example of where I use lengthened partials for mobility purposes is the hip adduction machine, since I have poor range-of-motion with hip abduction (i.e. spreading my knees apart),
With this exercise in particular, I manipulate the setup–pushing the backrest far forward and setting the range-of-motion governor to allow for the most stretch–so that I can achieve a deeper stretch at the lengthened end of the movement.
And, importantly, the weight provides the resistance I require to reach those end ranges of motion–similar to how a partner can help pull you into a deeper stretch during partner stretching.
Here are some other exercises I implement lengthened partials with in an effort to improve areas of weakness in terms of range-of-motion:
Dumbbell bench press (ironically, bench pressing with lengthened partials may actually help me reverse my hunched over posture I developed from bench pressing too much)
Lat pull-down (I get an especially deep overhead stretch when using the close-grip attachment)
Barbell Back Squats (I always use light weight when doing these, and I switch from lengthened partials to full range-of-motion repetitions at the point in the set when it gets challenging in order to avoid getting injured by being stuck in the bottom of a lengthened partial and not able to get up)
Conclusion
As I described in detail in my deep dive on range-of-motion, research suggests that lengthened partials lead to significantly greater muscle gains than shortened partials (i.e. half repetitions that cut out the stretched portion of the movement) and likely meaningfully greater gains than full range-of-motion as well. (I, III, IV)
In particular, in my recent training, I have been emphasizing lengthened partials for exercises that have a shortened biased resistance curve and those that are relevant for improving my mobility weaknesses.
Have you tried out lengthened partials or even emphasizing the stretched portion of the movement in full range-of-motion repetitions? Did you know that resistance training can be a useful way to improve mobility?
I’m interested to hear your thoughts and happy to talk about anything health and fitness related in the comments below or via direct message.
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