How best to combine muscles for weight training

Learn which muscles your body consists of and how you can combine them when weight training.

The muscles of the human body

The human body can be divided into 2 major halves:

1. Upper body
2. Lower body

The upper body can be defined as the area above the hips, while the lower body can be defined as the area from the hips down.

Both the upper and lower body have muscles on the front and back.

Muscles of the upper body

The front of the upper body consists of the following muscles:

• Pectoralis major (pecs or chest)
  Draws the arm inward, forward, upward, and downward; rotates the arm inward
• Sterno-cleido mastoid (neck)
  Bends the head and neck to the side; rotates the head and neck; draws the neck forward and backward
• Biceps brachii (biceps)
  Flexes the elbow; supinates the lower arm; raises the arm forward at the shoulder
• Brachialis
  Flexes the forearm toward the upper arm
• Coracobrachialis
  Raises the arm at the shoulder; draws the arm inward
• Foream group (forearm)
  Bends the forearm to the upper arm; bends and straightens the wrist; bends and straightens the tumbs and fingers
• Rectus Abdominis (abs)
  Draws the spine forward; compresses the abdomen; depresses the ribs
• Serratus Magnus (serratus)
  Rotates the scapula downward; draws the scapulae apart; assists in chest expansion; assists in raising the arms overhead
• External Obliques (obliques)
  Bends the spine forward and to the side; compresses the abdomen

The back of the upper body consists of the following muscles:

• Back group (back)
  Rotates the arm inward and outward; assists in swinging the arm backward; rotates, raises, and draws the should blades together
• Latissimus Dorsi (lats)
  Draws the arm downward and backward; depresses the shoulder girdle; assists in forced inhalation; bends the trunk sidewards
• Trapezius (traps)
  Raises and lowers the shoulder girdle; moves the shoulder blades; moves the head backward and to the side
• Deltoid group (delts)
  Raises the arm to the horizontal position; each deltoid head (front, side, rear) lifts the arm in a particular direction
• Triceps (triceps)
  Straightens the arm and draws it backward
• Brachialis (bracialis)
  Bends the forearm to the upper arm

Of the upper body muscles mentioned above, the chest, back, lats, and traps are large muscles.

Of the upper body muscles mentioned above:

• The biceps are the opposite of the triceps
• The chest and abs are the opposite of the back, traps, and lats

Muscles of the lower body

The front of the lower body consists of the following muscles:

• Quadriceps (quads)
  Straightens the leg; flexes the hip joint; rotates the leg inward and outward
• Tibialis Anterior (shin)
  Extends, flexes, and turns over the foot

The back of the lower body consists of the following muscles:

• Biceps Femoris (hamstrings or leg biceps)
  Bends the leg; extends the thigh; rotates the thigh inward and outward
• Gluteus Maximus (glutes)
  Extends and laterally rotates the thigh
• Gastrocnemium (calf)
  Extends the foot; assists in flexing the knee; assists in locking the knee back
• Soleus (soleus)
  Extends the foot

Of the lower body muscles mentioned above, the quads, glutes, and hamstrings are large muscle groups.

Of the lower body muscles mentioned above:

• The quads are the opposite of the hamstrings
• The shin is the opposite of the calf and soleus 

How should you combine muscles for weight training?

1. Train large muscle groups before small muscle groups
2. Train muscles opposite to each other

A best practice is to train large muscles first and then small muscles afterwards, because small muscles almost always assist and stabilize the motion performed by large muscles.

For example, if you decide to do calf raises first and totally burn out and waste the energy in your calf muscles, and then immediately after that do some squats or leg presses, you will find that your legs are quite shaky and unstable while doing the exercises for the large muscles. Consequently, the workout for the large muscles will suffer and be less effective.

It is also a good idea to train muscles opposite to each other to keep muscles in balance with each other. For example, when you are done training your quads (front of the leg), you could train your hamstrings (back of the leg). There are two ways to combine exercises:

1. Train opposite muscles right after each other in supersets
2. Train opposite muscles separately, but on the same day 

The first method is good if you want to increase endurance or if you’re looking to add variety to your workouts. The second method is good if you want to build strength or muscle mass.

In short, train large before small muscles, and keep muscles in balance by training opposites.