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Partial vs. Full Reps… or Both?

Partial vs. Full Reps…or Both?
By Menno Henselmans

A potentially game changing study has just been published. It may change how you perform your exercises forever. Or it may not. Let’s have a look.

The study titled “the efficacy of incorporating partial squats in maximal strength training” is about combining partial and full reps in your training. The debate on whether training with a partial range of motion (ROM) has any benefits compared to training with a full ROM has been going on for decades.

One reason many people have trouble understanding the effects of ROM is because they think ROM is equal to the distance a weight or body part travels. It’s not. ROM is equal to the amount of degrees a joint flexes. Look at the illustration of elbow flexion ROM below.

Partial

Now that we’re clear on the definition of ROM, here’s the Cliff notes on the current state of the research on full vs. partial ROM training.

Muscle Growth Research

  • In a study comparing Scott curls with a full compared to a partial ROM, there was a trend for greater growth of the arms in the full ROM group [2].
  • Research comparing full to partial squats, including unpublished work by exercise scientist Truls Raastad in Norway, shows that full squats lead to more muscle growth of the quadriceps than partials [6].
  • A full leg training program including squats resulted in more thigh muscle growth when performed with full reps than with partial reps [7].
  • Training the quadriceps at long muscle lengths results in higher muscle activation than training at shorter muscle lengths. This remains true when absolute or relative training intensity is held constant. In general, at long muscle lengths a muscle is under greater biomechanical stress (shorter moment arm, reduced cross-bridge formation and reduced force production per sarcomere). [9]
  • Over the course of a partial rep leg training program, quadriceps muscle activation decreased in the part of the ROM that wasn’t exercised [9].

Strength Training Research

  • Full reps led to greater strength development than partials for leg extensions, Scott curls and squats [1-2, 5-7, 9].
  • Full ROM bench pressing did not build more strength than partial reps in one study, but in this study ‘partial’ reps just meant avoiding the last 2-5 inches to lock-out [3]. Since the bench press has a steeply increasing strength curve, once you’ve passed the sticking point the last few inches are incredibly easy. So easy you may as well not do them?
  • A replication of the bench press study showed that full ROM bench presses did in fact lead to greater strength development than avoiding lock-out and keeping ‘tension on the muscles’ [4].
  • Partial reps build strength specifically in the part of the movement you train with limited transfer to the rest of the movement [1, 5-9].
  • Whether partials are better than full reps at improving the exercised portion of a lift varies. In untrained subjects study deep squats outperformed partial squats in building partial squat strength [5]. In a study on leg extensions partial reps were no better than full reps at any part of the movement [1]. In a study on recreationally active subjects there was no difference [7]. In a study on resistance trained subjects partial squats were better at building the partial squat than full squats [6].
  • In general, more advanced lifters and more complex exercises benefit more from partial reps due to the principle of training specificity. Beginners and simple exercises do not require ROM-specific training to induce maximum muscle growth and build strength across the entire movement.
  • Core training may be an exception. Research on back extensions found that training with a greater ROM did not benefit strength development in the spinal erectors [8]. Stuart McGill’s well known research shows the functional anatomy of the core is best suited towards stabilization, not actual movement. A full review of optimal core training is beyond the scope of this article though. They call these things bullet points and I already have more bullets than there are chambers in most guns.

Power Training Research

  • Full squats are better at developing power and jumping performance than partial squats [5-6]. This is a strong finding in favor of full squats. Partial squats have visibly greater movement specificity to jumping and result in higher power output than full squats [10]. Still, full squats are better to increase power than partial squats.

squat

Note that all the above research compared training exclusively with a full versus a partial ROM. Competitive bodybuilders, powerlifters and to some extent Olympic weightlifters still regularly train with partial reps, but they all perform partials in addition to full reps. This is where the new study comes in.

Combining full and partial reps: double the strength and power?

Bazyler et al. [11] compared advanced trainees with an average squat of 324 pounds (147 kg) on a program of either 6 sets of full ROM squats (group F) or 3 sets of full squats and 3 sets of partial squats (group FP). At the end of the program, the group performing both partial and full squats developed more strength and more power than the group that always used full ROM.

“There was a trend for FP to improve over F in 1-RM squat (+3.1%) 1-RM partial-squat (+4.7%), isometric squat peak force allometrically scaled at 120° (+5.7%), and impulse scaled at 50 ms, 90 ms, 200 ms, and 250 ms at 90° (+6.3 to 13.2%,) and 120° (+3.4 to 16.8%).”

Case closed: using both provides the best of both worlds, right? Not so fast. A few caveats are in order.

  • None of the measures of strength were statistically significantlydifferent between the 2 groups. Now this may have been due to lack of statistical power, but it’s certainly reason to take these findings with a grain of salt.
  • Moreover, in the sticking point of the squat, the full squat group gained a significant amount of isometric strength, but the full+partial squat group did not.
  • The full+partial squat group only gained more power on 1 measure (impulse scaled) and not the other (rate of force development) and it was only in the sticking point, not at the top of the squat. Even worse, the reliability of the results was low. Several results suffered from what statisticians call heterogeneity of variance, which basically means the 2 study groups were not strictly comparable.

Ok, recap: the results in favor of using both partial and full squats instead of just full squats to develop strength and power in the squat are questionable. Theoretically, however, it makes sense that incorporating partial squats increases power development. Partial squats allow for far greater power production than full squats [10]. If I ask you to jump, you will intuitively do a partial squat before jumping. No one sinks down into a full Olympic squat, ready for take-off.

When the results of a study are unclear, we need additional research. Fortunately, Bazyler et al. weren’t the first ones to study combined full and partial rep training. Massey et al. [3] compared groups bench pressing with an equal number of sets of either full reps or a combination of full and partial rep sets. Although the difference in strength gains were not statistically significant, the full rep group gained 25 pounds on their bench press compared to just 16.5 pounds for the full+partial group.

The authors replicated this study and found the almost exact same strength increases in both groups. This time, the strength difference was statistically significant: the full ROM group gained more strength than the full+partial ROM group [4].

These studies on the bench press provide strong evidence against the use of partial bench pressing. However, the subjects in Massey’s bench press studies were all only recreationally trained. As you read earlier in this article, advanced trainees may benefit more from the use of partials than beginners. In athletes, variable ROM training for the bench press improved power production even though it did not increase strength gains compared to regular full ROM training [12]. This corresponds with the findings by Bazyler et al. The subjects in the full+partial rep group gained less isometric strength in the sticking point of the squat, but their dynamic squat strength improved more because they became more explosive and could push through the sticking point better.

How can someone’s form be so bad yet so good at the same time?

How can someone’s form be so bad yet so good at the same time?

What about partials for muscle growth?

Here’s where it gets really interesting. The diets of the subjects in this study were not controlled. As a result, the average body fat percentage in the full squat group fell by 10.3%. Body weight did not change in either group and body fat percentage did not change significantly (-5.3%) in the full+partial group. The only way body weight can remain stable while fat percentage decreases is by gaining lean mass. So the full squat group must have gained more lean body mass than the full+partial group. I emailed the corresponding authors about this, since they did not discuss this in their article, but I have not received a response.

Full reps have several advantages over partial reps to induce muscle growth. Full reps activate muscles along their entire length (with the right exercise selection at least) [9]. Stretching a muscle under load is a strong stimulus for muscle growth. It results in the addition of sarcomeres in series and in parallel, basically creating a thicker and longer muscle [9, 11]. The addition of sarcomeres in series is also why heavy weight training over a full ROM increases muscle length while stretching does not increase muscle length.

In in vitro muscle cells, animals and bio-artificial muscles, the combination of muscle activation and stretching has been shown to strongly increase protein balance, anabolic gene expression, anabolic hormone signaling – particularly insulin-like growth factor-1 and mechano growth factor – and muscle growth [9, 13-18]. Basically, stretching a muscle or activating it is a stimulus for the muscle to remodel itself and prevent damage in the future. Combining stretching and activation is therefore optimal to create a stronger and bigger muscle.

On the other hand, there are some theoretical benefits of using partial reps for muscle growth, such as increased metabolic stress. However, this is likely only relevant when training at a low intensity when there is otherwise not enough tension in the muscle for high muscle activation. (If you don’t understand how muscle grows in response to tension, read my article on structural balance in Alan Aragon’s Research Review where I explain this.) So far, partial reps have at best resulted in equal muscle growth as full reps in research.

And yes, that means most pro bodybuilders are training in a suboptimal way. If you can’t fathom the idea that a largely poorly educated and underground subculture’s intuitive way of manipulating the human physiology is not perfect, you have much to learn about this world.

As much as I love these guys, I do not consider them the foremost authority on exercise science.

As much as I love these guys, I do not consider them the foremost authority on exercise science.

So how does this all fit together? It depends on your goal.

Conclusion: hypertrophy

Partial reps do not seem to have any advantage over full reps to stimulate muscle growth. Full reps stimulate muscle activity over the entire muscle’s length. They also stretch the muscle under high tension. Exercise selection and accommodating the resistance curve to your strength curve are generally superior methods of adding variety to bodybuilding training than partial reps.

Conclusion: strength

Including partial reps can be beneficial in advanced trainees to strengthen parts of a movement as per the specificity principle. Geared powerlifters in particular can benefit from strengthening their lock-out due to the lack of passive assistance they get from knee wraps, squat & deadlift suits and bench shirts at the end of these exercises.

Novices are better off building a good strength base by sticking to full ROM training, because they are not developed enough to require ROM-specific training.

Conclusion: power

Partial reps for many exercises allow for greater power production, which can benefit power development. Just as for strength training, these benefits are greater for more advanced trainees.

About the Author

MennoBayesian bodybuilder, popular science author and online personal trainer, Menno Henselmans helps serious trainees attain their ideal physique using scientific and Bayesian methods. Follow him on Facebook or Twitter and check out his website for more free articles.

Are you a fitness professional looking to further your education? Have a look at Menno’s course for personal trainers.

References

1. Specificity of limited range of motion variable resistance training. Graves JE, Pollock ML, Jones AE, Colvin AB, Leggett SH. Med Sci Sports Exerc. 1989 Feb;21(1):84-9.

2. Effect of range of motion on muscle strength and thickness. Pinto RS, Gomes N, Radaelli R, Botton CE, Brown LE, Bottaro M.J Strength Cond Res. 2012 Aug;26(8):2140-5.

3. An analysis of full range of motion vs. partial range of motion training in the development of strength in untrained men. Massey CD, Vincent J, Maneval M, Moore M, Johnson JT. J Strength Cond Res. 2004 Aug;18(3):518-21.

4. Influence of range of motion in resistance training in women: early phase adaptations. Massey CD, Vincent J, Maneval M, Johnson JT. J Strength Cond Res. 2005 May;19(2):409-11.

5. WEISS, L. W., FRX, A. C., WOOD, L. E., RELYEA, G. E., & MELTON, C. (2000). Comparative effects of deep versus shallow squat and leg-press training on vertical jumping ability and related factors. The Journal of Strength & Conditioning Research, 14(3), 241-247.

6. Influence of squatting depth on jumping performance. Hartmann H, Wirth K, Klusemann M, Dalic J, Matuschek C, Schmidtbleicher D. J Strength Cond Res. 2012 Dec;26(12):3243-61.

7. Impact of range of motion during ecologically valid resistance training protocols on muscle size, subcutaneous fat, and strength. McMahon GE, Morse CI, Burden A, Winwood K, Onambélé GL. J Strength Cond Res. 2014 Jan;28(1):245-55.

8. Limited range-of-motion lumbar extension strength training. Graves JE, Pollock ML, Leggett SH, Carpenter DM, Fix CK, Fulton MN. Med Sci Sports Exerc. 1992 Jan;24(1):128-33.

9. Electrodiagnosis in New Frontiers of Clinical Research. Edited by Hande Turker, ISBN 978-953-51-1118-4, (2013). Chapter 8: How Deep Should You Squat to Maximise a Holistic Training Response? Electromyographic, Energetic, Cardiovascular, Hypertrophic and Mechanical Evidence. By Gerard E. McMahon, Gladys L. Onambélé-Pearson, Christopher I. Morse, Adrian M. Burden and Keith Winwood.

10. Drinkwater, E. J., Moore, N. R., & Bird, S. P. (2012). Effects of changing from full range of motion to partial range of motion on squat kinetics. The Journal of Strength & Conditioning Research, 26(4), 890-896.

11. The Efficacy of Incorporating Partial Squats in Maximal Strength Training. Bazyler CD, Sato K, Wassinger CA, Lamont HS, Stone MH. J Strength Cond Res. 2014 Mar 20.

12. The influence of variable range of motion training on neuromuscular performance and control of external loads. Clark RA, Humphries B, Hohmann E, Bryant AL. J Strength Cond Res. 2011 Mar;25(3):704-

13. Muscle growth in response to mechanical stimuli. Goldspink DF, Cox VM, Smith SK, Eaves LA, Osbaldeston NJ, Lee DM, Mantle D. Am J Physiol. 1995 Feb;268(2 Pt 1):E288-97.

14. Mechanical stimulation improves tissue-engineered human skeletal muscle. Powell CA, Smiley BL, Mills J, Vandenburgh HH. Am J Physiol Cell Physiol. 2002 Nov;283(5):C1557-65.

15. Expression of insulin growth factor-1 splice variants and structural genes in rabbit skeletal muscle induced by stretch and stimulation. McKoy G, Ashley W, Mander J, Yang SY, Williams N, Russell B, Goldspink G. J Physiol. 1999 Apr 15;516 ( Pt 2):583-92.

16. Changes in muscle fibre type, muscle mass and IGF-I gene expression in rabbit skeletal muscle subjected to stretch. Yang H, Alnaqeeb M, Simpson H, Goldspink G. J Anat. 1997 May;190 ( Pt 4):613-22.

17. Changes in muscle mass and phenotype and the expression of autocrine and systemic growth factors by muscle in response to stretch and overload. Goldspink G. J Anat. 1999 Apr;194 ( Pt 3):323-34.

18. McMahon, G., Morse, C. I., Burden, A., Winwood, K., & Onambélé, G. L. (2014). Muscular adaptations and insulin‐like growth factor‐1 responses to resistance training are stretch‐mediated. Muscle & nerve, 49(1), 108-119.

26 Comments

  • Kenny Croxdale says:

    Menno,

    Good information. I’d like to add something from my training perspective.

    Complex Training Partials

    In 1998, I combined Partials with Power/Speed Training for my Powerlifts. Sixteen years later, I still employ this training method because it works.

    I began using this method after reading, William Ebben and Dr Phillip Watts, “A Review of Combined Weight Training and Plyometric Training Modes: Complex Training”, which appeared in the October 1998 Journal of Strength and Conditioning,

    As Dr. Donald Chu’s noted, “Complex training matches pairs of exercises from two sources: a resistance pool and a plyometric [power/speed] pool.” According to Chu, “[b]y itself, strength training will produce results, but not to the same level” as training simultaneously with a similar, explosive plyometric movement. http://www.liftinglarge.com/Building-Strength-and-Power-With-Complex-Training_ep_50-1.html

    The main theory as to why it works is that, “High-load weight training increase motorneuron excitability and reflex potentiation, which may create optimal training conditions…” Ebben/Journal of Strength & Conditioning.

    In other word, preforming a heavy movement tricks the CNS into producing a greater amount of explosive force in the power and/or speed movement that it would have without it.

    Partials

    What I have found is that Partials preformed prior to a power and/or speed movement elicit just that response, a much greater expression of power and/or speed.

    In this perspective, Partials a great method of evoking this response.

    “Conclusion: Strength”

    As you stated, Partials work for advanced trainees and geared Powerlifters.

    Another Version of Westside Training

    I look at Complex Training as another version of Simmons Westside method. A method of increasing Limit Strength and power and/or speed in the same session.

    With that said, one of the keys in Complex Training not to max out on a Partial/Limit Strength movement prior to any power and/or speed set. Doing so, will dampen power and/or speed production.

    Post Power and/or Speed Sets

    Maxing on a Partial/Limit Strength set needs to occur after the last power and/or speed set is performed.

    With that in mind, Partials definitely are a great method of increasing strength when the program is written correctly.

    Kenny Croxdale

    • Nice. The phenomenon you’re describing is called post-activation potentiation. It can be triggered with partial reps but also with full reps. Interestingly, however, there is some research including at least 1 direct experimental study that I can recall that shows that it’s better to do power and strength training separately than combining it in the same session. It depends on the exact skills you’re trying to develop for your sport/activity.

      • Kenny Croxdale says:

        Menno,

        POST ACTIVATION TRAINING
        Yes, I am aware that it is PAP. I co-wrote a magazine training article on it back in 2001 and makes a presentation on it at the New Mexico NSCA Strength Clinic that same year on Complex Training.

        I have used this training method since 1998, for 18 years now. So, I have a pretty good idea of the practical application of it.

        PARTIALS VS FULL RANGE LOADING
        With Complex Training, I have employed full range movement. However, overall I have found that partial range movement elicit a better response. Another topic for another time.

        POWER AND STRENGTH SEPARATELY
        While a major proponent of Complex Training, I would tend to agree that separating power days from strength days might work better via Westside Training.

        My question is how much better is it?

        Kenny Croxdale

  • Tom says:

    Thank you so much for this clear and well-written article. It supports everything I was suspecting already! And by the way: “If you can’t fanthom (…) about this world” made my day!

  • Rob Panariello says:

    Definitely an interesting discussion. Some additional thoughts for S&C coaches to consider regarding complex training based on the occasions NFL S&C Coaches Al Miller, Johnny Parker and I spent with Dragomir Ciorosain, my 30+ year relationship with my good friend Don Chu, and my 30+ year experiences of training athletes:

    1. Complex training is not effective in the untrained or low level athlete.
    2. The weight intensity portion of the complex must be heavy enough to provide a stimulus for recruitment as lighter loads performed at higher repetitions will induce fatigue
    3. When utilizing complex training, the athlete will peak earlier in their training vs. not utilizing complex training. This is a very important when considering the preparation of the athlete and the program design. Peaking early may or may not be advantageous depending upon the situation presented.

    Just my opinion

    Rob Panariello

    • I agree with points 1 and 2. I’m not sure if #3 holds in general though. I’d say it depends on the training program design, but complex training should at least make it possible to peak earlier.

  • asdf says:

    Are there any compound movements where the focus shifts from one muscle to another, in that if you wished to work on just one of those muscles, a partial ROM would be useful (I couldnt really think of any). Or, in any case, would an isolation exercise be preferred.

    Btw, the ‘strength curve’ article linked is fantastic

    • Glad you like my articles. The movements you’re describing, where different parts of the movement target different muscles, definitely exist. Examples include the Olympic lifts, handstand push-ups (vertical to horizontal body position) and muscle-ups. I generally don’t like these movements for body recomposition purposes though exactly because they generally train several muscle groups suboptimally instead of training fewer better (also why I prefer RDLs over deadlifts).

    • Anthony says:

      some exercises become more detrimental to joints in certain ROM . I consider flat bench press lockout one on these depending on scapular mobility or lack thereof. So shorting the ROM may be more about survival than potentiation.

  • This is pretty interesting. Years ago I tried half reps for a few months because of a book I read that advocated them. Not only did I see no difference in my results (I always log my workouts), but I took a lot of shit for even doing it – was told I was wasting my time. I’ve often wondered if it was fitness level that was lacking for them to be effective, or if the book was just junk. Hell, anyone can write a book, right?

    • Kenny Croxdale says:

      John,

      POWER FACTOR TRAINING
      This is the book you are talking by Pete Sisco/John Little book.

      Basically, the mixed fact with fiction and crowed themselves a the new “Gurus”.

      So, for the most part the book was junk.

      Kenny Croxdale

  • Trev says:

    Interesting read. Do you have any thoughts on the benefits or not of increasing range of motion partials, as practised by the likes of Paul Anderson and Bob Peoples? The idea of training from a strong to a weak point over time seems intuitively correct but I haven’t come across any studies on the topic.

    • I think it makes more sense to work on your weak points in general, but transitioning from partial to full ROM can help with strength transfer. It’s a viable way to incorporate partials.

  • JohnFinn says:

    Thanks for the information, I always had the idea that most experienced bodybuilders did partials because it was enough to stimulate hypertrophy and the opposite for strength building, that sure did clear some things for me.

  • Jeff says:

    I just want to say that partials saved my training career. When I was 25 I was all beat up from lifting and really thought about quitting lifting because I was in so much pain but then I read an article about partial reps written Brooks Kubic that said partials strengthen the tendons and other connective tissues allowing one to lift heavier weights in the full range without all the damage. Needless to say I’m 42 now and am stronger than ever and though not totally pain free all the time I can continue to keep training hard and heavy.

    The studies may have shown less muscle growth from partials but the first time I started them I gained 15 pounds in a month without changing my diet or anything else.

    Partials will always be a part of my training and now I am adding lockouts to my other partials to strengthen the tendons more and I expect greater strength gains in the near future.

    Here is a great article By Brooks on partials that everyone should take a look at.

    http://ditillo2.blogspot.com/2008/07/tendon-ligament-strength-by-brooks.html

    • Partials actually tend to have a poorer tissue stress distribution than full ROM training. There are many exercises where prolonged heavy lifting over a full ROM can be detrimental to connective tissue health (like the bench press), but that is related more to the strength-resistance curves I mentioned than the actual use of full ROM training. I’d recommend experimenting with accommodating resistance to see if that helps you use a full ROM without discomfort.

      Also, full ROM differs per person. Some people cannot squat to parallel or bench or deadlift fully. You have to find out what your (active) full ROM is.

    • Chris A. Rivera says:

      15 pounds in one month? Now is that 15lbs of fat, muscle, or bullshit? Lol, and without changing his diet.

  • Eric says:

    Very well done.
    A quick thought on power- with a partial Rep are you looking for a potential increase in power strictly from a anumbers perspective or power and its transfer for sports performance?
    Wouldn’t a partial neglect the biomechanical action of full hip extension and neglect sports specific carryover?
    Interested in your thoughts.
    Thanks and awesome article.
    -Eric

  • Amar says:

    WHat i came to understand is that some bodybuilders do partials after they failed on full rom to get more intense stimulus to the muscle for hypertrophy. like Tom Platz.

  • Matt says:

    This seems to be comparing partials in a more fully contracted positions as opposed to in the stretched position for the muscle. Generally partials being used by bodybuilders are done to stay in the portion of the lift with the most tension on the muscle. ie. near the position where the humerus is parallel to the ground during pressing movements. Bands could be used to continue resistance to follow the human strength curve. I am curious to see a study done comparing partials in a more stretched position rather than near lock out.

  • Jim says:

    Thanks for a thoroughly researched article and great read. Now I no longer feel bad about cutting partials out of my routine and stick to full reps.

  • Craig Ackerman says:

    Good article. One track of thought that has never been fully researched in sport training,is that each and every muscle contraction is a random event,meaning that a different pattern of fibers are fired on each contraction and are never the same due to recruitment and/or fatique thus the advantages for utilizing multiple reps in a set. Each time the muscle is even partially relaxed a different pattern of fibers and fiber firing frequencies are recruited on the following contraction. Much like gearing up or down in a car to compensate for speed and elavation.

  • bob says:

    It’s a no nonsense article backed by studies so an interesting read. I respond to both partial and full ROM training. I will say this in regards to partial ROM training. If it’s something new to you then you may be in for a pleasant surprise. I remember for a long time I was stuck at 310×10 for a full depth olympic squat. I’d only ever performed ATG squats for years. I tried all kinds of reps schemes and loads without progressing. It wasn’t until I got peeved at my lack of progress that I decided to get used to lifting 310 for high reps. I worked up to 310×35 limiting myself to parallel. When I did eventually switch back to full rom training again I’d comfortably pushed out 20 reps. The fact I wasn’t used to lifting heavy loads in a partial range of motion for high reps certainly caused an adaptive response far greater than I’d experienced through full range training. Unfortunately as with all things I soon became accustomed to partial rep training and progress slowed.

  • This is quite an interesting read and very well-researched. I always prefer partial reps myself but this is something that opened my eyes and I feel good about the stuff I do.

  • […] you’ve read my article on the effect of range of motion (ROM) on muscle growth on Bret Contreras’s blog, you should now understand the discrepant findings from the research team of Massey et al. They […]

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