We all know that exercising and training your body is very important and at least partly key to getting confidence.

I had some thoughts about that and came to the conclusion that it exclusively has positive effects on yourself and people around you. I will elaborate.

What lifting does is wonderful. You go out, lift heavy, work hard on improvement, and it rewards you with a boost of confidence. This confidence stems from different aspects.

One of them is the discipline you absolutely need to see yourself succeeding. This discipline then again consists of consistency and endurance.

Consistency means you set yourself a priority and you stay true to it over years. It's not a thing you put in between activities, it's a thing you do before doing other activities. This in return helps you getting your other priorities straight and living by those. You do less unneccessary crap and spend your time on important things, thus you will get more difinite in your actions, words and plans. Also you will set more definite goals for yourself.

Endurance on the other hand is strongly connected to consistency, but is another chapter by itself. Endurance means you start a thing, plow through it without hesitation, jump over hurdles and finish your work. I like to see it as dedication. You believe so much in your decisions that you 100% believe it's the best option available. This makes you focus on nothing else but your work and you will get your shit done. Also you have neither the time nor the energy to bitch about anything. You will stop complaining and instead change what annoys you. It makes you productive.

Second thing, which also is important to successful exercising, is your diet. (Here I'd like to mention that I am not deep into that matter and some words might be off context. I only know some general relations. If you find words used in wrong context, feel free to comment about it, but also elaborate. I'd like to learn about that.).
In my life, I ate fast food shit and food pumped with sugar, probably because it tastes intense. But it does nothing good to your body. You will lack vitamins, fatty acids and minerals. Because of that your body will not be able to produce an adequate amount of hormones that will get you through your day and keep your metabolism in check. Instead you feel tired and your organs won't work at 100% efficiency. Your skin will look bad, too. A healthy diet will make your metabolsim run perfectly, makes your body produce a good amount of important hormones and you have enough energy to do the work of two days in the time of one. Your skin will look clean, too. So, because you have enough energy, you will also have more positive attitude for doing things. A good diet makes your body healthy and helps keeping a good mindset.

Third, it gives you motivation. You see your muscles getting bigger. This was your goal in the beginning. You reach your goal and now you know how to get to where you want to be. It motivates you to work for goals.

Those are the effects on yourself that build confidence.

But there is more to it: The effects it has on your surroundings are those that signal confidence.

First, you get the physical appearance some will praise you for and a lot envy or hate you for, because they aren't able to reach that. And your Adonis-like body, of course, is very attractive. It signals a healthy state of body and mind, since you need both to get to a body like that.

Second, a strong physique equals physical strenght and because of that, you will rarely find someone messing with you. For some it's subconscious, some are conscious about it, but they respect your presence more than their own. You can de-escalate situtations by just stepping between two people and staring them down. Barely anyone wants to fuck with you because you can knock them the fuck out (drunk people and envier might be an exception though). You earn people's respect the second they see you and they avoid treating you disrespectful.

Third, with proper body language a good physique will make you seem even bigger than you are. Keep a good posture and you take up as much space as two people do. And taking up the space you want is a big indicator of confidence. People will notice and eye-lock you across the room, because you are like a boulder among gravel. People will see leader qualitites in you, since they can't help but noticing you first.

My conclusion is, like the advice you hear around here a lot, to go and work out. Do some sports, go to the gym, move your ass and do it over a long time. It is good for both body and mind.