Should you use poorer form to lift more weight for hypertrophy?

Recently I was asked a question that went something like this: “I see many people with good physiques on Instagram lift with bad form. Why? Should I do this, or should I maintain good lifting form but use less weight? If this type of form is suboptimal, how come their muscles are so well-developed?”. This is a common doubt that I know a lot of people have. So, I thought I’d address it with the aim of helping some people understand the ins and outs of this question and help them extinguish some of their doubt.

Executing exercises with improper form (such as using lots of momentum; incorporating body parts other than the target muscle to move the weight; twisting harshly at joints like the hip or shoulder to move the weight; reducing range of motion in order to lift more weight; neglecting to control lifting tempo in order to lift more weight) is a bad idea. To understand why, lets first begin with some concepts of hypertrophy training.

Mechanical tension is a main driver of hypertrophy [1, 2]. Mechanical tension can be modified mainly by weight used, time under tension, the reps performed and the distance of the weight traveled (note: time under tension and reps performed clearly have an overlap as more repititions = more time under tension, however there is a distinction in that the same number of repititions could be performed with a slower eccentric phase, causing increased time under tension). Clearly, lifting more weight is one way to modify mechanical tension, so no problem here. However, using improper form means this could be done the expense of other modifiers of mechanical tension such as time under tension and distance the weight travels (range of motion). Now, if we sum up all of these contributors of mechanical tension, then maybe this is equal, right? Maybe more weight and less of the other stuff versus less weight and more of the other stuff equal the same amount of mechanical tension (hypothetically speaking). Then what’s the problem?

Well, there’s a few actually. Firstly, research exists that is suggestive of increased range of motion (ROM) promoting better muscle growth irrespective of if more weight is used in place of range of motion (though with this occurring in some muscles more than others, based on current research) [3]. This makes sense to me given that 1) even if the weight is less, the distance the weight travels is greater, 2) you’re taking the muscle across an increased range, meaning the muscle can be trained across its entire length rather than only certain portions, and (3) the contribution of stretch-mediated muscle growth. Notably, it should be said that greater ROM does not always equate to greater gains in the literature, as strength and conditioning expert Chris Beardsley points out here [4]. Indeed, certain enhanced regional hypertrophy may occur as a result of partial reps in some muscles. But since full ROM training may have other advantages such as potentially lower injury risk and potentially better repitition standardisation, it may be desirable to incorporate regardless of if hypertrophic effects compared to partial range repititions are similar. More research may shed light on some of these theories in the future.

Another feature of full ROM training in compound lifts is that greater growth can be seen across more of the muscles involved in the lift. To demonstrate this, below is a picture uploaded by Greg Nuckols on his Instagram page. It shows a study that assessed hypertrophy of muscles involved in a squat between two groups — one group squatted with a full ROM and the other with a partial ROM [5]. Whilst growth was the same in the quads, significantly greater growth was seen in the adductors and glutes. (Also, for anyone interested, hamstring hypertrophy was very small, confirming that the squat is a poor choice of exercise for hamstring growth). Personally, I see this as large benefit because if you get more total muscle growth across different muscles in the body from a single exercise, it means you have to spend less time and energy training these other muscles with other exercises. Translating this to other compound exercises, it can be expected that similar results would be seen in, for example, the anterior delts of a full versus partial ROM bench press and the traps with full versus partial ROM pulling exercises.

A screenshot of a post made by @gregnuckols on Instagram looking at the effect of squat depth on various muscles involved in the squat. The results are taken from the study assigned to reference [5].

Next, you’re using other muscles to move that weight and not the taget muscle. In the video this manifests as swinging the shoulder and using the legs. This has multiple consequences: 1) You’re risking losing your mind muscle connection with the target muscle. Mind muscle connection refers to an intentional psychological and physical effort to place the stress on the muscle you want to train when performing an exercise for that muscle. Better mind muscle connection has been shown to lead to better hypertrophy likely by improving the quality of training on the muscle due to more focus leading to greater mechanical tension [6]. 2) You’re increase systemic fatigue whilst also obtaining no hypertrophic benefit. If your training is increasing fatigue without increasing the hypertrophic stimulus then you are not training effectively and reducing your own recovery capacity.

Third, your injury risk increases. Compared to performing exercises with proper form, improper form increases injury risk. I guess I don’t need to explain why this is bad, and if you’re interested in long term progress then this in itself should be a good enough reason to avoid improper form in place of correct execution. So all in all, this poor form is something you want to avoid and replace with good form for 1) possibly greater (and likely not worse) gains through greater ROM, 2) better recovery through lower systemtic fatigue, 3) better mind muscle connection and 4) lower injury risk. With all this being said, why do some bodybuilders train like this and still have so much muscle?

Replicating the actions of top athletes (in bodybuilding especially) is a logical fallacy with multiple reasons behind it. Let’s go through a few. Firstly, this style of training might simply be suboptimal for them in spite of the fact that they’re training this way. That is, we don’t know that they couldn’t be better if they did train a different way. As we stated at the beginning, lifting more weight will increase mechanical tension on the muscle. There is no doubt you can still grow with this training technique (Branch Warren and Bertil Fox are the prime examples that spring to my mind here), but it is highly unlikely that this training technique will be the most beneficial training technique you could employ. In fact, it’s highly unlikely it’s optimal for them, too…

Second, they may be training like that because they don’t really know much else. It may be much more dogmatic and much less of a calculated decision they are making, especially bodybuilders of the past where knowledge on optimal training methods was scant. Third, you don’t know what other exercises they do and how they perform them. Seeing a poorly executed row doesn’t mean all of their exercises are executed in this manner. They may perform others with better form, meaning we cannot base our logic that training in this way got them to where they are in terms of their muscular development. Fourth, many bodybuilders have been training many years and may have picked up injuries that restrict the way the can train. Again, this may not be a choice but something they do because they don’t have many other good choices (this applies less to the above video and bad form generally, but has some relevance to the conversation as a whole, for example if ROM is reduced).

But last and most importantly, top bodybuilders should not be replicated without good reason exactly because they are elite. That is, many bodybuilders have certain circumstances that apply to them that will not apply to the vast majority of people. Namely, 1) they have incredible muscle growing genetics that you don’t have and 2) they may be taking substances like steroids that enhance their growth. The genes of these individuals mean that they can train in a wide variety of ways and still grow. Alternatively, their recovery capacity may be exceptional, which means you can apply more mechanical tension through greater training volumes and intensities and still recover before your next training session to allow progressive overload. It’s likely that if some of these people never trained in their life, they’d still look pretty buff. These people train in various haphazard ways from a young age and still grow. This type of training for most people would not lead to much growth at all. There’s countless examples of this kind in bodybuilding, but one of my favourites is the owner of the greatest legs in bodybuilding. He trained with insanely high intensity, with many sets (I’ve read as much as 40 sets every leg session) and with poor form and cheat reps on certain exercises, and still grew the best legs ever. Go try that style of training — my guess is this will not lead to you owning the greatest set of legs you could possibly grow.

Tom Platz and his iconic legs

Then, of course, there’s the elephant in the room. Performance enhancing drugs give a huge advantage to building muscle. This means you can get away with suboptimal training and diet habits and still get great gains. This point is mostly of relevance when looking at your favourite bodybuilder or influencer on Instagram. If they’re using steroids, they could look a way that would basically be impossible without them and get there doing things that would not cause any meaningful muscle growth in someone who was not using them. I don’t think steroids are “cheating”, and in many ways I think they allow you to work harder and make things more difficult rather than easier, but I do believe it should be kept in mind in conversations like this because it alters the interpretation of the situation.

In closing, it makes sense that if you see a person who looks great performing a given exercise that you should also do that to look great but be aware of the pitfalls of thinking like this. Correlation does not equal causation, and their situation might not apply to you at all. Applying logic like this stops you from developing misbeliefs in the fitness and health industry that at best hinder your progress and at worst impact your health. Using certain types of improper form may offer some advantages like enhanced region specific hypertrophy and more weight or repititions during a set, but come with a host of disadvantages that likely outweigh these benefits over the long term.

Quick thanks to University of Kent PhD candidate and old friend Ryan Norbury for proof reading.

References:

[1] Krzysztofik, Wilk, Wojdała, & Gołaś. (2019). Maximizing Muscle Hypertrophy: A Systematic Review of Advanced Resistance Training Techniques and Methods. International Journal of Environmental Research and Public Health, 16(24), 4897. https://doi.org/10.3390/ijerph16244897

[2] Schoenfeld, B. J. (2010). The Mechanisms of Muscle Hypertrophy and Their Application to Resistance Training. Journal of Strength and Conditioning Research, 24(10), 2857–2872. https://doi.org/10.1519/jsc.0b013e3181e840f3

[3] Schoenfeld, B. J., & Grgic, J. (2020). Effects of range of motion on muscle development during resistance training interventions: A systematic review. SAGE Open Medicine, 8, 205031212090155. https://doi.org/10.1177/2050312120901559.

[4] Beardsley, C. (2018, August 29). Does a full range of motion always produce more muscle growth? Retrieved from https://medium.com/@SandCResearch/does-a-full-range-of-motion-always-produce-more-muscle-growth-5bf7fc6e4b55

[5] Kubo, K., Ikebukuro, T., & Yata, H. (2019). Effects of squat training with different depths on lower limb muscle volumes. European Journal of Applied Physiology, 119(9), 1933–1942. https://doi.org/10.1007/s00421-019-04181-y

[6] Schoenfeld, B. J. (2010). The Mechanisms of Muscle Hypertrophy and Their Application to Resistance Training. Journal of Strength and Conditioning Research, 24(10), 2857–2872. https://doi.org/10.1519/jsc.0b013e3181e840f3

Biochemistry BSc, current master’s student of Nutrition and Health at Wageningen University Research, the Netherlands, and lifetime natural bodybuilder.