The hardest muscles to train
If you ask anyone involved in weight training about what they find to be the hardest muscles to train, the chances are you’ll get the same answer: calves and forearms.
Out of all the muscles, calves in particular seem to get an indecent amount of attention and focus, with many dedicated gym-goers practically obsessing over getting their calves to grow.
Even Arnold Schwarzenegger dedicates a decent amount of attention to them in his autobiography, Total Recall, stating that back in the day he used to go to the length of cutting off all his trousers at the knee so he could see his weak point and motivate himself to train them.
Remember he’s probably one of the most genetically gifted bodybuilders of all-time, and still he appeared to have trouble in getting his calves to grow.
As a result of all this attention thousands of articles and routines have been written to help trainers ‘overcome’ this muscles stubborn resistance.
As always when everyone wants to know the ‘secret’ or the ‘key’ to results, this situation is ripe for good old-fashioned bs and fairy-tales in the name of shifting product and broscience advice.
Here’s my take on it.
You can’t really ‘grow’ big calves and forearms
Sorry, this is the truth of it. You know the person in the gym who has got big calves and developed forearms? Don’t even bother asking him for advice on his routine, because he probably doesn’t even train them directly.
Having well-developed forearms and calves is largely genetic.
The chances are if those parts are not already decently sized relative to the rest of you, you probably don’t have the disposition to build them by very much.
It boils down to the way muscle is built, through adaptation.
In case you didn’t know, your calves have been pushing your bodyweight around since the day you were born. Your forearm controls your grip, your hand, your fingers, as well as being involved everytime you bend your arm.
That is a lot of time and a lot of work to have been adapting to.
Since they are used so often and for usually long periods of time (think about the effort your calves produce when they have to transport your body around on a walk for an hour) they are made up primarily of endurance, or slow-twitch fibres.
You basically have two types of muscle fibre: slow and fast twitch.
Fast twitch (Type 2) muscle fibre is good for strength and power, and has a larger diametre. Slow twitch (Type 1) muscle fibre is for endurance and is smaller.
While generally you have around a 50/50 split of the two everyone has a slight genetic predisposition to their muscle fibre composition.
At elite level studies have shown that Olympic sprinters have up to 80% fast twitch fibres, while Olympic marathoners have 80% of slow-twitch. This difference is demonstrated in their performance and appearance: sprinters are more muscular and have better power, while marathoners are much smaller but can work for a long time without fatigue.
Can you change the fibre composition of your muscles through training?
You can certainly improve your power or endurance through regular training but obviously only to an extent: the reason why Olympic marathoners become marathoners is because early on it was obvious they were naturally better at running for a long time, rather than being fast.
They could knock themselves out at trying to be sprinters and put on some muscle, but they wouldn’t get very far compared to those guys who were born with more fast-twitch fibres and a predisposition to be fast and powerful.
With muscles like your calves and your forearms, it’s pretty random and genetic what mix of fibres you have there but on the whole you are likely to have more slow-twitch endurance fibres, due to the nature of the role these body parts fulfill.
If you’re genetically ‘lucky’ you might have more fast twitch fibre which means they will probably be larger, naturally, than someone who has put the same amount of work into them but lacks the larger fibre.
Size also depends on your muscle insertions
One major factor you have to take into account when discussing muscular potential is also the length of the muscle and where it connects to your bone.
All muscles are connected to tendons, which are in turn connected to the bone. If your tendon is quite short, you will have a longer muscle and therefore more potential for it to grow. If your tendon is quite long, the muscle itself will be short and therefore is limited in terms of space to grow: no matter how hard you train you can’t make a muscle longer.
So if your calf muscle connects to your tendon half way down your lower leg, you’ll have a smaller muscle than someone whose calf attaches closer to their heel.
Related article: Muscle: 5 real facts
You can’t change this. It is also genetic, and applies to all muscles in your body.
So…should I bother training them?
Evidently this is a personal question and depends on your goals. You can certainly push them to develop through doing heavy calf raises or forearm work like reverse curls.
Remember though how well adapted they are to stress. While you don’t very often use your pectoral muscles in daily life for example, you have been using your calves constantly since you were born.
The muscle is used to carrying around your bodyweight for thousands of reps everyday.
Therefore in order to make it grow, you need to give it a reason to. 4 sets of 10 reps standing on a step aren’t going to do much to a muscle as tough as the calf.
A similar, if less extreme logic applies to your forearms. They have been gripping and moving your hand since day one and therefore are used to performing thousands of tasks a day. If you work in a manual job they are already well adapted to grabbing and holding heavy things.
Obviously there is a lot more scope to develop your forearms than your calves because many people’s forearms haven’t been exposed to anything more strenuous than holding a pencil. But nonetheless the same protocol applies: you have to give them a reason to grow.
This is why doing heavy compound movements like deadlift or shrugs will help you apply the most stress to this area, and force it to develop.
Just don’t expect miracles if you don’t already have the genetics. Generally speaking the people training in the gym with the most developed forearms and calves will be the ones who have never really targeted them: they probably have just lucked out in the genetics stakes for those body parts.
But in a similar way you’ve probably got good genetics in other areas.
One of the best things about lifting weights or training in general is the exploration of your physical limits. You’ll find that you excel naturally in some areas and that other areas need more work: others will never be that good regardless of how much you train them.
It is a bit unfashionable to say these days, but sometimes you have to accept your limitations. Don’t believe anything or anyone that says natural physical limits don’t exist.
But it doesn’t mean you stop working. You just realise that when it comes down to it, the contest is always with yourself.
Can you be the best version of yourself? Only one way to find out.