Isolation exercises (single-joint) like curls and skullcrushers are often associated with building muscle and there's good reason for that. But don't spend all your time doing them. Compound exercises (multi-joint) like squats and deadlifts hit more muscles, giving you more bang for your buck per rep.
We've been conditioned to believe that 8-12 reps is the muscle-building range. There's some truth to that, but don't dismiss building strength with lower reps. Think about the people you've seen put up big numbers on squats and deadlifts—were they tiny? Probably not. That's because size often develops alongside strength, so neglecting one can cause more harm than good.
You need to eat a lot of good food to put on muscle. And unfortunately, it's all too easy to underestimate the amount of calories you're actually taking in. It's worth taking the time to figure out how many calories you're eating each day vs. how many you need to put on weight. Check out our calorie calculation guide to learn how to do this.
Patience is an unfortunate—and irritating—requirement in fitness. Proper recovery is a necessary part of the muscle-building process, and ignoring this is one of the easiest ways to derail your progress. Don't be afraid of off-days. They might make you feel like a lazy slob, but they're secretly transforming you into a badass.
It might seem obvious, but make sure you're hitting all the big muscle groups. It's easy to get caught up in what you enjoy the most and before you know it, you'll start to cut out the bits that you don't care for. You don't be the person with the massive upper body and skinny little legs, do you?
Your options for muscle-building supplements are seemingly limitless. You can use protein powders, mass gainers, pre-workouts, testosterone boosters, amino acids, and more to promote muscle gain. Each of these provides different benefits, so it's up to you to decide where you need the most help.