3 Guys Train Forearms Everyday - Only 1 Was Worth It
Fitness creator Jeremy Ethier documents a 30‑day experiment to grow his left forearm, which he has historically neglected. He recruits two friends: Robin, who does 100 daily hand‑gripper reps, and Denis, who follows a popular "rice‑bowl" grip‑training method. Jeremy follows a science‑backed gym routine that targets the three main forearm muscle groups – flexors, extensors, and brachioradialis – with wrist curls, extensions, hammer‑style curls, incline/preacher variations, and cable work. Baseline measurements (upper, middle, lower forearm circumference) and three grip strength tests (support dead‑hang, crush grip, pinch grip) are taken for each participant’s left arm (training) and right arm (control). Over the month the trio trains daily, noting soreness, joint pain, and adjustments (e.g., switching from dumbbells to cables, adding straps). Jeremy references a study where well‑trained lifters bench‑pressed daily for 34 days, using it to justify daily forearm work. Mid‑experiment data show Robin struggling with volume, Denis progressing with rice stirring endurance, and Jeremy experiencing wrist discomfort but finding joint‑friendly exercise swaps. At day 30 the results are compared: Denis’s rice training yields the most overall forearm circumference growth (upper region), Jeremy’s gym routine produces the greatest growth in upper and middle forearm with unchanged wrist area, and Robin’s hand‑gripper work boosts middle and lower forearm size. Strength tests reveal that the rice method improves dead‑hang endurance, the gym routine excels in crush grip, and the hand‑gripper method slightly improves pinch grip. Jeremy concludes with his top three forearm exercises (farmer’s carry, hand‑gripper, and a cable‑based brachioradialis movement), a twice‑weekly forearm routine, and a recommendation to reduce strap reliance. The video ends with a promotion for the Built With Science+ app, offering personalized workouts and nutrition tracking.
Chapters
Over the next 30 days, I'm turning this forearm into a powerhouse. Because after over 10 years of training, I always assumed my forearms would get jacked from normal lifting, but they didn't. And my forearms are now the second smallest part of my body. Even worse, people have started noticing. And weak forearms don't just affect how you look. They can hold you back in the gym, are linked to shorter life expectancies, and have even been shown to decrease your odds of being hired. So I'm training my left forearm every single day using science-backed exercises. But I've also recruited two friends to test the most popular forearm protocols on the internet. So by the end of the 30 days, we'll know which method and what exercises actually build the biggest, strongest forearms and wrists. But first, we need to get our baselines. Because all of us are right-handed, we're gonna be training our left arms for the experiment with the right arm serving as a control. We're taking measurements across our lower, middle, and upper forearms to see if our different training programs grow some areas more than others. This is the smallest one I've ever measured. Shit! Ah! And while for this experiment size matters, what matters even more is who can last the longest. Ah! Shit! Doesn't count. What the fuck? This simple test measures your support grip, which is essential for rock climbing, deadlifting, and even bringing in your groceries. And for this one-hand test, most beginners should be able to hang for 10 to 20 seconds, with 90+ seconds being elite. No, this is so hard. Keep going, keep going. And with Robin holding on for a max of 12 seconds— 12 seconds! It's not 12 seconds. It was my turn. And while I'm hanging, I should probably explain this is just the first of multiple tests we'll be using to assess our grip strength, which can actually be broken down into 3 different types. And while I am feeling pretty good about my support grip, Okay. 115. When it came to our next test, the results were a bit more humble. Normal. 121.4. Normal? I'm about to break this. This second test measures our crush grip. Think if you're trying to crush an apple with your bare hand. I felt your handshake. It's like a little girl. Oh! Oh! That was pretty high. 9908. 9908. I still cannot hit 3 digits. That's as hard as he goes. To make Dennis feel better, multiple studies have found the average person's grip strength today is far weaker than it was even just 20 years ago, which is problematic since grip strength is one of the best predictors of your overall strength and activity level, which explains why researchers found a strong correlation between weak grip and early death. Ugh. Robin, don't pass out. Okay, 108.2. And for our final test, we're measuring finger and wrist strength by testing our pinch grip by attempting to hold 3 10-pound plates between our fingers and thumb. Wow. And after struggling in our first 2 tests, this time Dennis just couldn't get it up. What the— this is so embarrassing. I'm a fitness guy. Yeah, so I'm sure you Center it, center it, center it. Zero. But then it was Robin who put both myself and Dennis to shame. No way. My, my foot will go. Your foot? That was pretty good. 6 seconds. Now for our training. Surprise. Oh, okay. This is going to be yours. You're going to be training your forearms just through gripping. Here we go. Robin will be sticking to 100 reps every single day with a hand gripper as his only training. Meanwhile, Denis will also be training daily, but he'll be using my leftover rice. Denis is trying the rice bowl approach that I've seen everywhere online, with people documenting some pretty crazy results. Robin and Denis will be trying to compete against my science-based gym routine that I've designed to maximize growth. But in order to design the best workout possible, we need to understand the 3 main areas that make up your forearm. Starting with the most beefy part of your forearms, the flexors. To train them, it's pretty simple, wrist curls. I'm gonna try these with dumbbells, but also some cable variations to see what works best. But if you lift weights, your flexors are already trained indirectly, so you're probably lacking a bit more in the next area, the extensors. These muscles sit on top of your forearm, creating some pretty crazy striations when you develop them, and may also help with elbow pain. Now to train these, you just gotta extend your wrist, which I'll be trying out with dumbbells as well as this cable version. Last but not least is this big chunk of muscle that sits right around your elbow crease, which is in my opinion the most noticeable, impressive forearm muscle. It's called the brachioradialis. Now unlike the two other muscle groups, this muscle doesn't cross over the wrist and won't be trained through wrist movements. It instead helps bend your elbows during curls, but so do your biceps. So to target this muscle more, you'll want to first rotate your arm into a neutral hammer grip. If you do just this during regular curls, you'll already feel the difference, but you can take it a step further. So I've been paying close attention to some really cool bicep studies, and it seems like placing your arm on an incline bench or preacher curl puts your biceps at a disadvantage and forces your brachioradialis to work harder and experience more growth. So I'll be doing one exercise that applies that, as well as reverse grip curls, which also seem to target this muscle well. I'm gonna give all these exercises a shot, training each area of the forearm with 3 sets to failure every single day. And after 30 days of experimenting, I'm gonna share what I think is the number one exercise for each area, plus give you a fully optimized forearm workout based on my findings. But by the time I had finished just my second workout on my new plan, I was already wondering if my forearms were even going to make it the full 30 days. My forearms have never been this sore before. Clearly, I don't train them. I don't know if I'm going to be able to do this for 30 days. So it's like hurting here and around the fingers. It's hurting a lot. First exercise, grab rice. 2. And while Denis doesn't have 100 reps to worry about like Ravn, Hey, no, no. He'll be following a popular Rice training plan that we found online. Now, I always thought training the muscle every single day just wouldn't allow it to recover and grow bigger and stronger. But some new research is making me rethink that. Because in a recent study, strong, well-trained lifters bench-pressed every single day for 34 consecutive days. They did one set where they tried to lift as much as possible for one rep, and then afterwards they did 5 lighter sets for volume. Now, you would expect training like this every single day would burn most lifters out. But by the end of the study, the lifters made insane strength gains, adding an average of 40 pounds to their one rep max, which for well-trained lifters would normally take easily over a year to accomplish. Now, while the study focused on bench press, may not be the perfect model for how to grow your forearms, my hypothesis is that short daily training shouldn't be anything to worry about, and if anything, may end up getting me the fastest gains of my life. But by day 3, I was already feeling a lot of discomfort, not just to my forearm muscles, but in my actual wrist joint. Oh, that hurts. That's so uncomfortable. And when I checked in with Robin, he was having a similar struggle trying to hit 100 reps every day. In fact, the only person who wasn't struggling so far seemed to be Dennis. This feels kind of nice. Today I'm doing legs, so I'm doing Bulgarian split squats. Usually I wear wrist straps on both. I'm only going to wear a wrist strap on the right side. If I'm being honest, I actually think relying too much on lifting straps is a major reason why my forearms have become underdeveloped. Because ever since I found out about a study that showed lifting straps instantly increase people's deadlifts by around 40 pounds, I started adding straps not just to my deadlifts but to all my back and biceps exercises. And so my forearms just simply stopped getting challenged. So now I'm trying to make up for all that missing activation. But because a common issue beginners have is their forearms and grip giving up before their other muscles like biceps and back. I'm curious if Denis, even with his rice training, will experience some benefit in his exercises where he typically gets forearm cramps, which is why on day 1 I also had Denis, Robin, and myself test our personal best on the incline biceps curl. And on day 30, we're going to retest to see if the forearm training of our left arm actually leads to better curling strength compared to our right. And since Dennis and I are already tracking our workouts through our Built With Science+ app, we'll be able to see if there are any other strength jumps that happen as a result of this improved grip. Ravan, on the other hand, he doesn't have a current workout plan, but he does have his own motivations. When I play piano, uh, I'm not good with the left hand. I always play right hand more. I'm really excited also how this exercise will come out. Impact me playing with left hand. And while we'll have to wait to see if Robin's playing improves, his progress with his grip training is already improving. He's already smashed 100 reps on the lowest difficulty, which means he can start upping the resistance, which meant I was the only one who was continuing to struggle with the daily workouts. Okay, so one thing I've noticed about a lot of forearm exercises, specifically for this guy right here, the brachioradialis, I found that dumbbells It's really hard to get the form down without aggravating the wrist and elbows. So I'm going to experiment with cables. Keep my palm facing down. Oh yeah, way better than dumbbells. With some exercise swaps, my joint pain was no longer an issue, and I even found some home-friendly exercises I could swap in when I didn't have a dumbbell. But the craziest improvement by far was the visual change I was already noticing. It actually feels like new begins again. Feels like I'm a beginner, just like my muscles are growing super quickly, which is really motivating 'cause I haven't had that since I started lifting. Even my wife seems shocked by my progress, asking me the one question every guy wants to hear. Why is it so big? What do you mean? Like, is your other one miniature now? Let me see your other one. But it feels pretty— like, it feels bigger. Well, it looks like it, but it feels pretty jacked though, right? Yeah. But size doesn't mean much without functional strength. So after 15 days of training, I wanted to see if each of us could pass a simple grip test. Today we're going to do a general fitness test. Usually you take 100% of your body weight and you have to do a farmer's carry for at least 30 seconds. But since we're only training one arm, we're going to divide that weight in half. And we're going to do that for 30 seconds. 3, 2, 1, go! All right, walk. Oh, easy. Come on, Robin. This 30-second challenge is a pretty reliable benchmark for assessing your grip strength. If you can make it the full 30 seconds, your grip strength is performing as it should be. You pass. But if you fail— keep walking, keep walking— Robin's down, Robin is down. You've got serious work to do. No, man. You passed. Good job. He doesn't get an high five. He didn't pass. He gets a low five. You have 2 weeks to pass this. Okay. And while Dennis and I did manage to complete our farmer's carries, Dennis's forearm has gotten so strong that regular rice is no longer challenging. Oh, I got these to increase the resistance. These are like metal bowls. So I'm going to add them to the rice. Hopefully when I do my workout, make it a little bit harder. We also got him a wooden spoon to make it more difficult. It's a lot heavier for sure. Oh, I would say like 5 times more difficult to do. As for my own training, everything was going good until week 3. I am frustrated. My lifts this week have been horrible. Like my forearm strength has tanked. I'm a little worried because my forearms feel exhausted. I don't think they're recovering well, but I'm hopeful that in the final 2 weeks that my strength really starts to pick up. Fingers crossed. Seeing my strength start to dip was definitely concerning, but when I look closer at the data on the Daily Bench Press study we talked about earlier, some days the people got stronger, some days they got weaker, and for many days it stayed the exact same. But by the end of the 34 days, all of them got significantly stronger than when they started. So I'm hoping if I just stay the course, I should be able to break through this plateau before we get to the final test. Every single day I can see the progress. Basically, I'm able to comfortably do the exercise now. Uh, this exercise definitely helped me to basically learn this. And after 30 days, Robin was getting stronger and stronger with his hand gripping, and he'd even made it to the hardest setting. Oh, I'm not sure the parking lot was the best place to do this. Meanwhile, Denis couldn't wait to stop carrying his rice bucket everywhere he went. Even if I'm on vacation, my arm's not going to be on vacation. As for me, I realized how much my arms benefit from direct forearm work. It took under 10 minutes a day, and I could easily fit it in between sets. Plus, I started relying on straps less and my grip more. But here's what I didn't expect. After experimenting with dozens of exercises, there were only a few that didn't hurt my joints. So I narrowed it down to my top 3 for growth and the exact workout I'm going to stick with after this. I'm going to show you all of that in a second. But first, let's see how my strength results compared to Denis and Robert. And what they don't know is I've also prepared a bonus test. What Reddit claims is the world's hardest jar to open. But we'll save that for later. Up first, is our crush grip. Oh my God, 137.2! I can feel that too. But for Dennis's rice training— show the camera, show the camera! Okay, that doesn't count, doesn't count. 86. One more time, one more chance, one more time. I thought he was going to break it. This is 604. What? Were you eating rice also? I'm predicting that this is going to be the biggest strength increase for Robin because this is what he trains. Go, Robin. No way, no. Before was 108. No, no, no way, no way. Oh, you got it. 1:11.4. Yeah, but last time you were— which meant round 1 is going to my science-backed gym plan. As for the dead hang— oh, 1:12. My time came in almost exactly the same as my day 1 time, which isn't the progress I was hoping for, and it means either Denis or Robin have the chance to take the win. Let's go, Robin. Easy work. What the— wait, wait, wait, wait, wait, what is— 6 seconds. 5.59. Not 6, 5. What was his last time? 12 seconds. Yeah, what happened? So hand gripper does not help with your dead hang time. Which means it's down to just Denis. And even though Denis claims his rice bucket was barely a full workout, His single-arm dead hang was already well past his day 1 time of just 5 seconds. Holding my breath too. 14 seconds. What have you been doing? Holding my breath helped. Also, I'm sick, so I think that helped. What I think also helped Denis is the fact that his rice workouts mainly challenged his grip endurance, building up to longer and longer sets of stirring the rice. Plus the fact that he was regularly lifting weights throughout this process. But what really surprised me was what happened when we retested our biceps curl strength. Our rep performance on our left side increased more than our right sides did, something I was not expecting, especially for a well-trained lifter like myself, suggesting that stronger forearms may in fact lead to strength boost in other lifts as well. However, when we tested Robin, who doesn't lift any weights at all, his results hadn't changed. But when we got to the pinch test— Oh! 20 seconds! 20 seconds? Holy fuck! Wow! Let's go! Holy— And even though I did improve slightly from day 1, compared to Robin, my extra second just doesn't feel very impressive. 6 seconds! Yo, how'd you do that? 20 seconds? So across the 3 tests we ran, it seems like each method of training did a better job at improving different areas of grip strength. However, when it came to our bonus test, Fuck it. Fuck it. Oh no, again. Oh my God. Again. Same expression. I swear it's the— Hey, hey, hey, hey, hey. No, no, no, no, no. You can't do none of this funny stuff. God, God, look at it. It's so painful. Now it won't be this painful if you're following the right workout plan using our Built With Science+ app. With it, you're gonna get a completely customized workout routine based on your body. And not just for your forearms, but for every single muscle. That way you're not gonna be embarrassed the next time you try to open a lid, or even take your shirt off at the beach. I had high hopes for you. Really? You can't open it? You're not joking? It also guides you with your diet and lets you track your nutrition with a snap of a picture. You can try it for 2 weeks free over at builtwithscience.com or by scanning this QR code right here. All right. Yeah, yo, I'm nervous. I don't know if I can Publish this video. What? Oh wow, look at this. You guys want some jab? But now let's talk about growth. So when we measured the average growth across all 3 measurement points, 3rd place went to Dennis's rice training, leading to modest growth through his upper forearm but no growth through his middle and lower forearm. Followed in 2nd place by me. While my forearms experienced a ton of growth through the upper and middle of my forearm, the lower part around my wrist stayed exactly the same. Robin, on the other hand, he had barely changed his upper forearm, but the highest growth around his middle and lower forearm. However, because of his training experience, he probably experienced the biggest newbie gains out of all of us. First time in my life I did any exercise. It's the first time in your whole life you've done exercise. Yeah, hopefully these gains convince Robin to commit to something more than just gripping. But based on my data and my own 30-day experience, here are my picks for the top 3 forearm exercises. And I've even added all of these forearm exercises to our Built with Science+ app. I will say farmer's carries as a bonus at the end of your workouts is a great idea, especially for beginners. And as we saw with Robin, simply getting a hand gripper is an easy, low barrier to entry way to get started. And might even grow the lower forearm a little bit more. And here is the workout I'm personally going to be sticking with going forward, doing it twice a week on my leg days or rest days. And if you want to pair your forearm training with a full body workout plan that hits every single muscle, then check out this video next. Thank you so much for watching, and I'll see you next time.
