abdomen
The biceps brachii, deltoid (anterior portion), brachioradialis and brachialis are used when you lift a glass to drink from it. The shoulder girdle muscles are also involved, including the trapezeus muscle across the top of your back. Chest muscles (muscles of respiration) are secondarily involved.
If you are referring to the dumbbell bench press, which works both arms independently, then the muscles being worked are mainly the pectoral and tricep muscles. Other muscles that are indirectly involved are the shoulder (deltoids and trapezius) and the lats (latissimus dorsi).
There are several factors involved in getting stronger muscles, not just lifting itself. The amount of reps you're doing, diet, and the consistency with which you lift are all factors.
It can be, because if your hands are to close together, you are isolating muscles, make it harder to lift. If the weight is distributed over a wider range of muscles, or stronger muscles, the lift is easier.
The shoulder muscles
your muscles burn when you exert yourself because when you lift heavy or lift for an excess ammount of reps you get a build up of lactic acid in your muscles
Pectoral Muscles, Biceps, and Triceps.
We have muscles so you are able to lift things and do everything we do on a daily bases .
Your arm muscles work by contracting and releasing to lift a mug of coffee to your lips. The muscles flex and contract to move your arm.
Lift weights with them
intercostal muscles
lift weights in the gym.