If you haven't already done so, including a few sets of heavy barbell squats into your weight training routine each week is perhaps one of the best things you can possibly do. Why? Simply because there's no other exercise that is more important for building muscle mass (except maybe Deadlifts).
Doing squats properly gives you the potential to pack on huge amounts of muscle mass onto your body. They are by far the most important leg exercise you can do, yet their benefits don't stop at the legs.
Many people regard squats as the single most effective exercise for muscle gain, because of the overall growth that results from doing them. Squats don't just pack muscle onto your legs, your entire upper body will benefit from them as well.
How will squats affect upper body? Well, since barbell squats (or dumbbell squats) requires a lot of strength and energy to perform due to their high level of difficulty, they force your body to release more amounts of vital anabolic hormones like testosterone and growth hormone. This enables you to pack muscle mass onto the whole of your upper body as well as your legs.
This means that by doing squats you will see an increase in strength all over your body. For example, including squats into your weekly routine will increase the amount of weight you can bench press almost instantly. Pretty useful if you ask me!
So why is it that so many people don't include squats in their workouts? Since they are such a difficult, uncomfortable and painful exercise to perform, people will do anything to avoid them.
There are a lot of reasons out there that stop people performing squats, but I really should call them myths because that's what they are. Excuses such as "they are dangerous to me knees" or "they are dangerous to the heart" are just that, excuses.
Squats are only dangerous when performed with improper form. So if you get the technique down right, then you're set for amazing muscle mass gains all over your body.
If you're not already squatting, why not start now. You'll be glad you did in a few weeks or so when you notice the great benefits from doing them.
Learn to perform barbell squats the correct way with our article:
How To Do Squats: Proper Squat Technique.
Hopefully this article has helped, but always remember to never get stuck in research land. Information is great, but what's infinitely more important and the only thing that actually matters to get results and change your life is to be hitting the gym week in week out, with a properly-structured, intelligently-crafted (based on science-backed principles) and overall well-balanced strength training and nutrition plan to effetcively build muscle as a skinny guy (AKA a lifting hardgainer). When you have a great program used by other successful hardgainers that have gone before you, you can't go wrong if you simply stick with it.
But here's the thing:
You don't just randomly stumble upon a highly-effective program that's designed specifically for hardgainers by simply browsing a popular fitness magazine, site, or forum (or asking your average run of the mill personal trainer at a local gym who is highly likely to be just repeating the same old ineffective, incomplete mainstream advice they learned in the classroom). No, instead, to create the best weight training and nutrition program for maximum results, you must be a little more selective in the program you choose to follow.
So, here are the 3 different paths you can take to guarantee you follow a finely-tuned, effective program that will leave nothing to chance and give you the best muscle building and strength gains of your life (again, if you simply execute and don't quit after a mere week 'cause you don't notice a change...).
See our flagship 7-step introductory guide to building muscle for beginners which covers all the basics you need to know, and guides you through designing and creating an effective program for muscle gain without getting fat. If you don't want to spend any money buying a pre-made program or finding a (good) personal trainer, and/or you're the DIY type who enjoys researching every little detail and knowing about how everything works and fits together, this is probably the path for you if you have the patience.
If you don't want to take the time to plan your own natural bodybuilding plan from scratch, following an already made, high-quality, credible program from a true expert in this field can save you a ton of time.
It can give you a great head start on your transformation journey and makes things a whole lot simpler as it's simply a matter of understanding what the program involves, how to do perform all the exercises, how to execute on the included meal plans (taking into account your own perferences as you'll want to tweak any pre-made diet plan for your own needs), and then simply executing week in and week out.
Sean Nal's popular hardgainer program is the one I currently recommend most, as it's the most complete, easy to follow program for beginners that I've seen (and I've experimented with many over the years). It's also the exact program that initially changed everything for me and I owe a fair part of my overall hardgainer success (going from 132lbs/60kg to 220lbs/100kg - mostly muscle) to being fortunate enough to having stumbled upon this program when I was struggling with gaining weight and building muscle. See my full review of Sean Nal's program here.
Path C: Find a (Good) In-Person Trainer
This isn't for everyone though as a quality trainer who knows what they're doing, and most importantly has got great results themselves (ideally starting out in similar shoes to you) can be quite costly. This is the path you should probably really consider if you have any type of serious injury though.
Whichever path you choose, never forget the single most important thing: never give up, and your success in transforming your body, strength, health, posture, and self-confidence will simply be a matter of when, not if. I'd say good luck, but if you really understand that last sentence, you're not gonna need it, friend. I wish you nothing but success.
Mad-Scientist of Hardgainer-to-Hero Transformations for 12+ Years
Last and Definitely Least: Certified Fitness Instructor (real-world experience > school)