An introductory guide to making gains, for the skinny guys out there.
Here are what I believe to be the most important factors for skinny guys to make gains—the key principles—plus some subsidiary strategies which may also help you out.
You can see from the picture that, although I didn't become a hulking beast, with proper training and dieting I also don't look like I'll be broken in half by a strong gust of wind. If you want to add some beef, here are the things I consider to be most important:
Follow the simple equation
calories in - calories out > 0
The complexity comes in other ways, such as (a) How much should calories in exceed calories out and (b) Does it matter where the calories come from?
To answer question (a), weigh yourself every day. Measure your caloric intake every day. For accurate measurements, use a scale to weight your food if possible. If you're eating out then approximating is okay. Many restaurants publish nutritional info online. Also start guesstimating your caloric expenditure per day, accounting for things like whether you exercised, biked to work, did a lot of walking, etc. Record these three metrics every day: weight, calories in, and calories out.
Start tracking these numbers in a speadsheet, and you will see over time how you need to adjust your
calories in to speed up or slow down weight gain. For me personally, an average increase in weight of 0.35 lb. per week seems to work well. It is close to the sweet spot for putting on muscle without also putting on too much fat.
Also note that just because a caloric surplus of 400 calories per day has gotten you in the sweet spot of +0.35 lb/week for the past month, it won't necessarily keep working. Bigger engines need more fuel, so as you get heavier, you may need to eat more to keep gaining weight at a steady pace. I've also found the reverse to be true, that sometimes weight gain happens too rapidly and I have to back off my diet. That's why it is important to track these things consistently, so you are aware of how your body reacts over time. Taking a picture of yourself once a week can also help you identify what works and what doesn't work in terms of the
calories in - calories out equation.
A final note: some programs poo-poo on calorie counting, and maybe that works for you. But if you really have no clue how many calories you eat per day, I would suggest counting for a month or two until you have a rough idea of how much you are consuming. From then on it's up to you.
To answer question (b), in short, it kind of matters where the calories come from. The most important thing is to make sure you eat enough protein. I suggest high-quality protein sources such as chicken, beef, eggs and fish rather than protein powder. Besides that, the best foods to eat should be common sense: fruits and vegetables, complex carbohydrates, and healthy fats such as avocados, nuts, and coconut oil. Stay away from hydrogenated vegetable oils such as those found in some peanut butter brands and flour tortillas.
Eating junk food is okay in moderation, just don't go too crazy. I've tried dirty bulking at 1000+ caloric surplus per day with Ben & Jerry's and other junk food. It doesn't work as well as a balanced diet (obviously!). You'll gain muscle this way, but also a lot more fat than if you eat reasonably clean.
You need to hit the gym bro!
If all you do is eat more, you'll just get fat!
The type of training you do should depend on your goals. Do you primarily want to get stronger? Do you only care about gaining size? Do you want to maintain some semblance of cardiovascular fitness? These goals are not necessarily mutually exclusive, although having a specific goal in mind will help you pick a training program. Regardless of what you pick, I believe the squat and deadlift will deliver the most bang for your buck and should generally be prioritized in strength training.
If you're just starting our, I recommend getting strong before you try to get big. The reason being, if you train for muscle hypertrophy by doing 5x10 squats at 135 lb., your gains will not be as good as if you first get strong enough to do 5x10 squats at 225 lb. Building a foundation of strength allows you to lift more weight when it comes time for high-rep workouts and hypertrophy.
If you are focused on gaining size (a.k.a. "muscle hypertrophy"), there are countless programs to be found on the Internet and most of them will probably be fine. Pick one that has an emphasis on the tried-and-true compound lifts. Stay away from weird programs with fancy exercises which could lead to injury. Really the important thing is that you go to the gym consistently to pick up heavy objects and put them back down again.
A good program should have a foundation of safety, enjoyableness, progressive overload, and proper volume and frequency. What I mean by the last two is that you should aim to hit each muscle group at least twice a week (frequency) and perform 10-20 sets per week on each muscle group (volume). These variable can be tweaked as you get more advanced, but more is not always better. Recovery is one of the most undervalued aspects of a good training plan.
They both have intricacies and complexities of course, but don't fuss over it too much. Especially if you're starting out. If you are a skinny dude who wants to add size, seriously just start eating more and working out.