Do muscle groups need to be trained differently?

The above question has cropped up quite a lot recently, due to the new movement on Glute growth, both in Males & Females. I think it’s safe to say that we must thank Bret Contreras for the pedestal that the Glutes have now been put on, but this question has loomed for the dawn of time (or since people wanted to start to grow muscles).

 

Firstly, we will discuss in Lehman’s what components we need to make a muscle grow. The components of training needed to create growth include the following; resistance training of a sufficient intensity, (mainly relative intensity in terms of proximity to failure) sufficient volume & frequency of training, & then progression of said variables (mainly in volume) over time. This is under the assumption that technique is at a level that allows for these variables to be applied whilst minimising risk of injury.

 

These variables are like the calories to a weight loss diet. Training, in terms of muscle growth, doesn’t get you anywhere if these components aren’t within it. I know this is a broad splatter of paint on the wall, but what I’m trying to illustrate, is that these things should be your first port of call when it comes to training any muscle group (skeletal muscle). These things don’t change (in terms of the variables needed, not the magnitude of each one) no matter what muscle group we are discussing.

 

Along with these variables that pertain particularly to muscle growth, we need to consider the training principles in general. The essential principles being specificity & progressive overload. Theoretically, you could have the perfecting endurance plan, with progressions in volume week by week, fatigue management built in & a phase potentiated model, but this doesn’t get you anywhere when it comes to muscle gain. If your goal is muscle gain, for the period that you are attempting to do it, you need to set up training so that all variables are specific to the processes of muscle growth (the variables we discussed already).

 

Progressive overload is important when we want to continue to improve. An overload, in our context, is something that presents the body with enough of a specific stimulus, to get a positive outcome based on our goals. An overload alone is sufficient to grow SOME muscle, but to continue to grow muscle, we must continue to progress the magnitude of that stimulus.

 

If we are being specific in training, & producing an overload that increases over time, we will continue to grow muscle (obviously, I’m completely negating the need for a nutritional input, but we are discussing training here). Within those confines, we need to consider the following:

 

1.    Are we doing enough work 2. Is that work hard enough 3. Is this work being performed frequently enough that we can recover from the work we have done, without negating future work so much that the effects are a net negative.

 

So is that it? No differences between muscle groups? Fortunately (or unfortunately) no. There are going to be differences between optimally (hypothetically) training different muscle groups. We can sort of split these into two sections; first the physiology, & then the practical application of training, but I’m going to put them together for ease.

 

The main differences in training between muscle groups will come in the following; the amount of volume they can each perform per unit time (a week for example), frequency in which a muscle group can be trained & then how exercise selection & mechanics affect things like intensity, rep ranges & more.

 

The amount of volume a muscle group can perform will depend on a few things (aside from individual difference); the amount of force a muscle can produce (because of fibre type, exercise availability & more) & the amount of range of motion a muscle group can go through as a result of training (particularly eccentric/stretch load).

 

Generally, the more force a muscle can produce & the more range of motion it can go through, the more recovery time is needed to return to baseline. Therefore, there is a lesser ability to perform more volume than their counterparts that produce less force & range of motion. These differences in recovery time are mainly due to the fatigue caused by producing higher forces (both locally & centrally) & then the increased muscle damage that is caused by larger loads being used during the stretch portion of the movement (more muscle damage usually results in longer time to recovery).

 

A practical example is to compare an RDL (Romanian Deadlift) & a lateral raise. The Hamstrings are generally large relatively, & primarily fast twitch dominant. This means that they can produce high forces (as seen in sprinters). Along with this high force capability, the range of motion available (depending on the person) & ability to stretch the muscle under load is high. Now contrast that with the force capabilities of the Delts (fairly low, especially the medial & rear portions) along with the real lack of ability to stretch the muscle sufficiently under load (you would have to literally intersect your own body to get a comparable stretch to the hamstrings).

 

The level of soreness you feel after a hard session involving some RDLs vs. a session of nearly as many lateral raises as you’d like isn’t even comparable, most individuals will struggle to put their socks on after a leg training session the day after. This high resultant muscle damage to the Hamstrings, means that we likely can’t perform as much volume per session. If we were to perform high volumes per session in such a muscle, it would likely lead to such long recovery times that it affects our ability to perform volume chronically (likely the primary driver of hypertrophy). We also likely can’t perform as much volume per week, as even low volumes of full ROM RDLs cause significant levels of soreness in most people.

 

Generally, the Deltoids can perform higher volumes than the Hamstrings,  as a result of lower force output, lower muscle damage & generally lower levels of fatigue as a result. So, whereas you may only be able to do heavy hip hinges 1-2 times a week, side & rear Deltoids could be trained nearly every day with a decent amount of volume, whilst still recovering & adapting (not always, but hypothetically).

 

A way to attenuate the above, is making sure that after you have done enough volume on your highly effective (although damaging) movements, you can look to get some more volume in with less damaging work (leg curl variations for example), that still contribute to total volume, but have lower fatigue per unit of volume compared to the RDL say.

 

We will now look at  how exercise selection & mechanics can affect training, in terms of how we set it up. Generally, the larger, more stable & multi joint exercises are likely more suited to higher loads, both in terms of efficiency & safety. Compare back squats & bicep curls. Which would you rather perform sets of 5 close to failure on? I know what I’d pick (hint: not bicep curls). So, some muscle groups may deal better with higher intensities than others. A good general rule, is that exercises involving smaller muscle groups, primarily isolated in their function when training them (i.e. bicep curls pretty much just elbow flexion vs. squats involving the ankle, hip & knee) with less stable positions, do better with repetitions of 8 & upwards. The bigger, multi joint & more stable exercises likely allow us to dip into the lower rep ranges a little more safely & effectively (although outside of a low volume block, I don’t really see the need for muscle gain purposes).

 

Thank you for reading this far, I hope that this hasn’t been a mind blowing read (or maybe I do I’m not sure), & that you have some new thinking points to take away & discuss. I’d love any feedback, & any questions can be directed to our Instagram @myonomics or email us at aaron@myo-nomics.com.

 

Aaron

Aaron Brown