Why am i not gaining weight ?!

Make sure you're doing the correct exercises. Compound exercises. Squats, bench, power cleans, over head press bent over rows, pull ups, push ups etc. Avoid isolation's like bicep curl, tricep extensions, leg extensions.. Stuff like that doesn't make you bigger.

Compound exercises boost your testosterone and get your hornmones goin so you get bigger. You're working with multiple muscle groups when using compound exercises. Make sure you're doin 3-4 sets and train in the 6-12 rep range (consisting of 30 seconds). Don't be Speedy Gonzales. Take your time during each set so you feel the burn.

Sports..

well... u need loads of carbohydrates and fats to make you gain weight and then u will know u r gaining weight! Its probably cuz u exercise u r not ganing weight!(thats considered good 4 most people!) thats all i know!

moi