Today I was working out on my arms spicificaly benching it was at the end of my work out and I was trying to do one set of 135 for benching the most I have ever done was 6 but today I only did one and I know I am weaker because all the other exercises prior to that but this is unacceptable and my friend pushed out nine which is better than what he had done last week 8 we both take whey protein I just don't understand. Also my abs seem to be fading away and I don't know why I have not been eating more and my work outs are the same please help also if this helps I am a 16 year old male who has been working out 5 days a week and have been doing this since october/november

Don't try going for personal bests at the end of workouts. If you work intensely, your muscles will be tired before you start, and you won't be able to lift as heavy. Do your heavy moves (bench, squat, deads) early in your workouts, keep lighter moves like curls and kickbacks for the end of the workout.

If you are working out hard, and not eating more, then you will run into trouble.

Can you post a typical day's food, and a typical workout?

In the morning before school I run then eat a breakfast shake and A banana for breakfast I eat a snack like a cereal bar for a snack for lunch ill have carrots and ranch dressing and a cheese stick before my workout. I alternate lower body and upper body to every other day first ill use the treadmill or elliptical for ten minutes to get the blood flowing then if I'm doing upper body that day ill do curls, a for arm workout,shoulder workout and some tricept work then benching and after that lat pull down and I finish with some abdominals after my workout ill have an apple and a whey protein shake. If I'm relly for my work out ill run again then ill eat dinner

A couple of things strike me.

You have very little good quality food protein in there. A shake is fine after lifting, but the rest of the day you should be eating real food, including good quality protein. All you've got is a banana, carrot, cheese stick and a cereal bar. That is not nearly enough food.

If you want to build muscle, you've not only got to work the muscle to the point where you cause micro-damage to it, so that the body repairs it bigger and stronger than before, you've also got to eat enough to keep the muscle going, and to build big muscles, you've got to eat more than that. Bulking takes a surplus of calories. Your body can't make muscle out of thin air.

I suggest eating something like porridge and eggs for breakfast, and perhaps something like a tin of tuna and some salad with an olive oil dressing for lunch. A cereal bar and carrot is not going to get the job done.

Also, a lot of cardio tends to make it harder for your body to build significant muscle. Enough to get you warmed up and to keep your heart and lungs fit is great, but too much will make you skinny, not muscular.

If cardio is important to you, do it on a different day from your lifting.

In the gym, once you are warmed up, do your big lifts first. So bench press definitely comes before curls and tricept extensions. Otherwise, your smaller arm muscles will already be exhausted by the time you come to bench, and your chest muscles will never got a good workout.

Start with big compound lifts like bench press, military press for shoulders, pull-ups or bentover barbell rows for backs, dips for triceps, etc. Keep the curls, lat pulls, extensions etc for the end of your workout.

On your lower body day, keep squats, deadlifts, stiff leg deadlifts, lunges for early in the workout, and things like calf raises and knee extensions for the end.