If you’ve been lifting weights for a while, you know how frustrating dealing with stubborn muscles can be.

While the rest of your body may be growing steadily, there’s always that one lagging body part that just can’t seem to develop.

If you’re new to this whole exercise thing — welcome, by the way! — it may be best to start by focusing on building some overall strength first, by using compound/functional exercises. Still, if you know that you’re going to want massive arms, picking up a few tips might be just what you need to get the size you want.

So, with that in mind, here are some tips that might just help with those pesky lagging muscles.

Building Biceps

Let’s talk about the hardest muscle first: biceps. Frankly, your triceps will be worked pretty thoroughly during your chest day. Your biceps on back day? Not so much.

Believe it or not, biceps are some of the most common lagging muscles among most lifters. Oh sure, everyone loves to talk about how much people ignore their calves and forearms, but those same critics barely challenge themselves when it comes to developing size in their biceps. Plenty of people train their biceps, but most people are just too comfortable with their current training program to push themselves any further.

So, if you’re looking to put on size, first order of business: start lifting heavy. At least 70-80% of your 1-rep max (the maximum amount of weight you can lift for one rep). This probably sounds like a no-brainer to you, but it’s important to keep this in mind. The heavier you lift, the more that muscle is going to break down. The more it breaks down, the bigger it will eventually become. There is no size without lifting heavy, guys. Plain and simple.

A great exercise for size? Well, your standard bicep curls are a good place to start. Personally, we’re fans of dumbbell hammer curls and preacher curls when it comes to isolation.

Sidenote: if you’re new to lifting weights and have one arm that seems weaker than the other, focus on using dumbbells instead of bars in general. Symmetry is critical when it comes to building a strong, impressive body.

So remember: lift heavy, isolate, and make an effort to focus on balance. Do all that and you’ll have bigger biceps in no time.

Tackling Triceps

Triceps probably aren’t the first thing you think of when someone says “bigger arms.” Most people aren’t walking around the gym, bragging about their huge triceps. Generally, the focus is on building bigger biceps. Still, remember what we said about symmetry earlier? We meant it. Developing those triceps is a vital part of getting that “big arms” look (especially if you’re struggling with developing your biceps). Beyond that, developing stronger triceps will help make your other compound lifts that much easier.

When it comes to triceps, isolation is going to be your number-one priority. There’s definitely a place for functional movement exercises when it comes to training arms (pull-ups are great for bicep development, and dips are one of the best exercises you can do to develop strength in your triceps), but if you’re going after size, isolation exercises are going to make up 80% of your workout.

Rope tricep pulldowns are a classic for a reason: they work. Beyond that, the close grip bench press is an exercise that can really challenge your triceps (without engaging your chest, if done properly). Finally, we have the EZ-bar Skullcrusher, an exercise that, when done properly, is a great addition to an already intense tricep isolation workout.

Getting bigger arms isn’t just about the look. Sure, it’s great to have size, but there’s no denying that having bigger, stronger arms can make a huge difference in the rest of your exercises. For some guys, arms are a muscles group that don’t receive the proper attention they deserve.

Legs, chest and back are all important and valuable, but if you’ve got weak arms, you’re going to have a physically-incongruent body. Translation? You won’t have the balance you need and you won’t be the strongest version of yourself. Take the time to bring those lagging body parts up to speed. You’ll be glad you did.