yo dude im 180cm, and used to be 60kg. In 3 months, i gained
7kg. sitting at 67kg now. So i still have a pretty low BMI, but
note that that 7kg is pure muscle.
key is to keep eating a shit load. go to the gym. take whey
protein within 40 min of your workout.
in terms of the gym, do muscle isolation. I mean, i spend 2 hrs
doing just chest, but i have a passion for the gym, so u really
dont have to do tht. so one day chest, one day back, one day legs
and arms... and so on. change your routine every month and a half
to shock your muscles.
to bulk up, lift heavy, less reps. to tone, lift light, lotsa
sets. 30 sec break between each exercise.
within each routine change the exercises every 2 months to shock
ur muscles as well. do different kind of sets as well.
Right now im doing burn sets for my back, rack sets for my chest
and drop sets for my arms. Burn sets is 3 reg sets of 6-8 and last
set do 30 reps with a drop in weight. So i do 140pounds for lat
pulldowns, i would drop to 90 pounds and do 30 reps. rack sets are
2 rack sets and 2 reg sets. so in the rack set, you start at your
heaviest weight and you steadily drop it 3 times. So i use 65
pounds dumbell flat bench. drop to 45 pounds. drop to 30 pounds.
drop to 15 pounds with no rest in between. trust me at 15 pounds,
its gonna feel like 100 pounds. drop sets are similar but you dont
go across the span of the rack.
search scott herman on youtube. He has some good tips.
gd luck bro. most important thing here is your drive, dont lose
it.
Isolation isn't the way to go for beginners (I'm still a
beginner). You will easily get muscular imbalance.
Compound exercises are the way, i.e. squats, deadlifts, bench
press, military press, chin ups, parallel bar dips. You get to
train more muscles at one go for the same amount of time... For my
limited time in gym, all I do are these exercises I mentioned.