What full-body exercises can I try for building strength with minimal mass? I am 15, 130 lb, 5'7, and am not very strong. Also take note that I don't have equipment and am not able to go to the gym. Could you please give a detailed specification for the exercises i would need and the amount of reps and sets.
Thanks
I highly doubt it is possible for you, given your age,weight and height to train and NOT get any mass gains.
In theory you could do heavy compounds such as deadlifts, squats and bench press. To minimize muscle gains you should normally only do single reps with high weight relatively to your strength (high intensity). But even then, the muscle gains would not be zero.
Doing one rep work all the time is not possible because it will lead to injury. You also do not have as you said access to equipment so all that is out of the question. Anyhow, your goal should be to minimize muscle gains not eliminate it. It is impossible to train to gain strength without gaining any muscle especially as a beginner.
If you have zero equipment and you do not want to buy any I suggest that you accept that it is practically impossible to do bodyweight exercises and seriously gain strength without gaining any muscle. This is because you will do mostly do higher rep work which builds little strength (it mostly grows your muscles or builds endurance depending on the rep range you are working out with). Now that may be false because you could find something so heavy to put on you that you can do heavy triples with normally body weight exercises (but this seems impossible unless you have access to some very heavy, dense stuff such as concrete).
Have in mind, since you want strength, muscle gains will highly facilitate strength gains. Strength depends on your CNS and your muscles. Thereby if you want optimal strength gains you should also grow your muscles. I do not see why you would want zero muscle gains but I will keep on answering your question as this is your goal. Nevertheless, I don't think there is any way to train your CNS without using your muscles and hence making them grow.
All in all, in my opinion you should do two things:
Accept that you can't have zero mass gains if you want to gain strength, especially without any equipment.
Try to do your best with what you have. You should grab something heavy, put it in a bag which you can wear for extra weight, buy a pull up bar if it is possible and do push ups, pull ups, pistol squats at a rep range below 5. This seems pretty basic but so are the options you have since you have no equipment. You might be able to do more complex stuff depending on what stuff you have available at home enabling you to improvise.
PS: All this seems pointless to me. I suggest you readjust your goals about not gaining mass. Unless by mass you also mean fat which then renders my answer useless. If by mass you also mean fat, then just pick any good bodyweight routine available and try to eat around maintenance calories.
The major exercises to get you stronger, without weights or any equipment must be 'compound' exercises, meaning they work out multiple major muscles in your body simultaneously. Examples of these are: press-ups, squatting, chin-ups using a bar or even a high wall and a form of overhead-press (either by using something heavy over your own head, or head-standing using your arms with a wall to support you in case you lose balance).
The amount of reps and sets simply depends on how strong you are. Some of these will be difficult to begin with, but once you get to the stage where you can do 30 reps of each exercise using your own body weight you will be far stronger than you were when you started.
Hope that makes sense.
Recycling my answer from another (duplicate) question: if you don't have access to a gym or other fitness equipment and your goal is to increase your strength, look at the Recommended Routine on Reddit. This routine of bodyweight exercises, carried out consistently over time, will hugely improve the strength of an untrained individual. As a consequence, you will also add muscle and lose fat. The overall effect on body mass will likely be neutral, but body composition should improve.
In order to add significant (>5%) body mass as a result of any resistance exercise routine, you need to undertake it for a significant period while also maintaining a significant ongoing calorie surplus. To get big, you need to eat big. If your diet is sufficient for your activity (but not in surplus), you won't increase in size.
