It really depends on the exercise. if you're using your arms, like pull-ups or push ups, then its your upper body, if you're using your legs, like jumping and running, then its your lower body, and if you're curling in your body or lifting up your legs or twisting, its probably your core.
Bones.
Supraspinatus, infraspinatous, teres minor, triceps brachii, deltoids and the trapezius muscles are used. Use the internet to find ways to do the Overhead Press.
The muscles used to lift the leg while lying down are primarily the hip flexor muscles, including the iliopsoas and rectus femoris. These muscles work together to flex the hip joint and raise the leg off the ground.
To grip a bat, you use the muscles to contract the fingers. To lift it, the preceding muscles and all the arm, shoulder and back muscles.
The primary muscles used to lift and carry a saddle are your biceps, triceps, pectorals and deltoids. To build up the muscles, you can lift weights, targeting those muscles.
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).
Biceps function to lift your forearm up to touch your shoulder. They are often used in cooperation with the muscles in your back to lift heavy objects.
The primary bone used in the arm to lift weight is the humerus. It connects the shoulder to the elbow and acts as a lever for the muscles that facilitate lifting. The muscles, particularly the biceps and triceps, work in conjunction with the humerus to perform lifting motions.
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
The biceps brachii, deltoid (anterior portion), brachioradialis and brachialis are used when you lift a glass to drink from it
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