4 arm day mistakes that are killing your muscle gains

Building big, superhero arms is more than just a vanity project. Stronger arms not only make everyday activities easier, they can improve athletic performance, boost posture, and lead to better bone density. That being said, there’s nothing wrong with simply wanting a good pair of guns in your short sleeve tee or dress shirt for the summer season.

Whether you use dumbbells, a barbell, resistance bands, or even just your bodyweight, there are plenty of ways to beef out your arms at the gym, or at home. However, if your gun show is currently more of a no-go, despite upping your protein intake and training consistently week upon week, you’re probably wondering what the heck is going on.

Thankfully, Jeremy Ethier, founder of Built With Science, sheds some light in a YouTube video, on four simple mistakes you may be making that are causing you to leave gains on the table. Pen at the ready...

4 ARM DAY Mistakes I Wish I Fixed Earlier (SLOWING Your Gains!) - YouTube

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1. You're targeting your arms from one angle

A bicep curl and tricep extension in some variation often dominate arm day. Training both is key, especially the triceps, which can often get left behind, as it makes up more than two-thirds of the arm. However, Ethier says most people tend to train the two with their elbows held by their sides. “What you have to realise is that the biceps and triceps are composed of multiple heads which can each be selectively emphasised based on how you orient your arm angle when you train them,” he explains. It’s therefore important you incorporate exercises that switch up the angle of your arm so you can target the different muscle heads, thus building well-rounded, 3D arms.

2. You’re ego lifting with poor form

It’s common knowledge that we need to optimally challenge our muscles to create microtears, so they grow back bigger and stronger. However, if you’re lifting stupidly heavy weights, and sacrificing your form in the process, you’re just stalling your gains (and it's a one-way ticket to injury). “For muscle growth, what’s more important than the weight you lift is actually activating the target muscle and placing it under sufficient tension during your sets, and that is always most effectively accomplished by using a weight you can control,” Ethier says. So, put your ego aside and worry less about the weight (or that of the person next to you) and use a weight that’s right for you. You’ll also look less silly too.

3. Your rest periods are too short

You may think taking a 60-second rest between your bicep curls is best, especially if they’ve delivered a mean pump. That must mean it’s working, right? Well, no. By not allowing your muscles to fully recover, you’ll most likely be going into your next set fatigued and probably won’t be able to hit the same number of reps or use the same weight as you did before. Ethier also refers to this 2016 systematic review, which reveals that resting for more than 60 seconds leads to 40% more muscle growth. So, don’t rush, take your time and let your heart rate come back down.

4. Your exercise order is all over the shop

Research says that for strength and hypertrophy, your exercise order should be “based on priority of importance”. If you therefore want to build well-balanced arms, Ethier says you shouldn’t just be doing all your bicep exercises at the start of the workout, and then leaving the triceps till the end. As we mentioned earlier, the triceps make up a bigger portion of the arm. Unless you want to focus on one area of your arm more, because the other is already well developed, Ethier’s advice is to alternate between the muscles you start with every week, or using supersets to target the two.