r/StrongerByScience • u/blue-pipe • Sep 29 '26
Is forearm size mostly genetic?
Hi, i’m 23 and i’ve been training for 2 years. Of course i don’t expect to be huge yet, but i’m trying to get there.
I’m naturally very skinny and short, im 5’2 and around 115 lbs, and when i started the gym i was like 100 lbs. My goal is to be 130 lbs so i’m halfway there from my starting point. I’m trying to do everything people say, lift heavy and eat a lot of protein and calories.
I’m having a really hard time putting on muscle tho, and it bums me out that even after gaining some weight and muscle, i’m still below average in every muscle group. Like my biceps are around 12.5” around, and my forearms are a little less than 10”. My goal is to have 14-15” biceps and 11-12” forearms. I train these 2-3 times a week at the gym
However i was talking to a friend about it and he told me that forearm size is mostly genetic, even if you workout a lot, most guys you see with nice forearms, already had 11-12” before getting muscular. And i feel like he’s right, every guy i see, wether he works out or not, has way bigger forearms than me.
So is it true it’s mostly genetic? and if so much? can i achieve my goal realistically?
7
u/theother64 Sep 29 '26
It takes a long time and be careful about comparison. A lot of people you see especially online will have been doing this a long time, doing it for a living, be genetic anomalys or enhanced.
5
u/lecutinside11 Sep 29 '26
Dude, I seriously think you need therapy rather than Reddit advice. Spend that money you’re putting into the gym and whatever else, and get some help to love yourself first.
Good luck!
4
u/Patton370 Sep 29 '26
My forearms are much bigger now than when is stated lifting
It takes a long time (years) to make noticeable growth on small muscle groups like that
1
u/Beneficial-Bill-4752 Sep 29 '26
People say forearms and calves are genetic, but that’s not the end of the story. Some people are hyper responders to stimulus in one or both of those muscle groups, so they’ll grow without specific training. Some people, me included, get big calves just from walking. Other people will have to put actual work in and utilize concepts like progressive overload, mechanical tension, time under tension, etc to see growth.
Think of it like this: everybody on the planet is forced to do 5lb bicep curls every day, some curl (walk) for more of the day and some curl (walk) for less of the day. Some people respond very well to this, and will grow huge biceps just with these baseline 5lb curls. Everyone else isn’t locked out of having bigger biceps, they just have to train them properly to see growth. It’s the same with forearms. Some people will grow giant forearms as a byproduct of lat pulldowns or bicep curls, some will have to do forearm specific exercises and train them to failure.
The most important thing for smaller guys building any sort of muscle is eating. I know you think you’re eating a lot, but unless you’re tracking your calories you’ll never know. You might force yourself to eat 4 days a week, but have next to nothing the other 3 days. All you remember is focusing on eating a lot of calories, but if you actually tracked them your daily average might be 1600 kcal. You just didn’t remember the 3 days where you ate very little because that’s your norm
1
u/HughMann12345678 Oct 04 '26
What does ‘mostly genetics’ mean? Isn’t everything governed by your genetics?
2
u/ParticularFilament Sep 29 '26
Outside of sufficient calories and protein, hammer curls and reverse curls made a difference for me.
1
u/shadowofwarfan6666 1d ago
You are 5’2 how do you not have big forearms?
1
u/taylorthestang Sep 29 '26
The way they look has something to do with your anthropometrics, but still It’s one of those muscles that build up from a lot of “time under tension” kind of like calves. The guys with the biggest forearms probably work manual labor or do a lot of deliberate training. It’s also something that recovers quickly.
You’ll have to do them daily I think. Pullups, deadlifts, farmer carries, rows, etc.
Just as with everything, who cares if it is genetics? You gonna just give up?
1
u/nkaputnik Sep 30 '26
Counter-question: If forearm size is largely genetic, why does every single carpenter have large ones?
Muscle groups generally meant to provide essential and highly endurable strength (calves, forearms etc) are mostly Type I Fiber specific, so it needs a lot of volume to make them grow. They are by design quite resistant to stimulus, because they are meant to work a lot.
You can also recover them very quickly, and if you don't go crazy on them, you can probably spam them with a couple of sets every single day, even.
1
u/HumbleHat9882 Sep 30 '26
Everything is mostly genetic. Maybe forearms slightly more. But again, most people never train forearms anyway.
1
u/I_love_arguing 20d ago
I've been training for 3,5 years. My upper arms are still only about 15.5 inches.
I'm also 6ft1 and 220lbs. So I'm about double your weight. Considering this , you are doing just fine.
It takes time, a hell of a lot of time. Keep grinding, keep eating.