Prepare for Weight Training by Understanding Muscle Groups - dummies

By Dan DeFigio, Nashville personal trainer and author of Beating Sugar Addiction For Dummies

In order to put together a complete weight training routine, you must first figure out which exercises work which muscle groups. Then you can apply that knowledge to a well-designed routine.

Muscles of the legs and hip

The muscles in the front of the thigh are called the quadriceps (‘quads’). Their main function is to straighten the knee. A nearby and related group is the hip flexors, which pull the knee up towards your chest.

The hamstrings are the muscles in the back of the thigh. They have two main functions: bending the knees, and in conjunction with the glutes (butt muscles), they pull the leg behind you (a movement known as hip extension). The glutes are also responsible for pulling the leg out away from the body. This is called hip abduction.

The muscles on the inside of the thigh are called the adductors. They pull the leg in towards the centreline of the body. This movement is called (you guessed it) hip adduction.

In the lower leg there is a group of muscles known as the calves, which push the foot down (point the toes). The group in the front of the shins is called the dorsiflexors. They pull the foot and toes up towards the shin.

So you can sound intelligent at cocktail parties, the movement your calves produce (going up on your tip-toes) is called plantarflexion. The opposite movement (toes up towards the shin) is dorsiflexion.

Torso and back muscles

Moving up to the torso, the chest muscles, or pectorals (‘pecs’) pull the arms inward towards the centreline of the body, like a hugging motion. The shoulder muscles — deltoids — pull the arms out away from the body until they’re overhead.

The functions of the muscles of the back are slightly more complex. There are large muscles in the upper back called the trapezius (‘traps’), and the rhomboids. Their main function is to pull the shoulder blades together. The trapezius, in conjunction with other muscles, also shrugs, depresses, and rotates the shoulder blades.

There is a pair of big, V-shaped muscles in the back called the latissimus dorsi (‘lats’) which pull the arms down towards your ribcage and behind you. Other muscles in the rear part of the shoulder are also very active during this pulling down movement.

The muscles that run along the back of the spine are called the spinal erectors. They are also known as the ‘lower back’ muscles, even though the group runs all the way from your sacrum up to the skull. The spinal erectors, together with some deeper muscles, bend the spine backwards — a movement known as spine extension or back extension.

The abdominal muscles (your ‘abs’) consist of the rectus abdominis, the obliques, and a bunch of deeper stuff that all move and stabilise the spine. The rectus abdominis runs from the sternum down to the pelvic bone. Its function is to round the spine, thus pulling the ribcage and pelvis together and flexing the torso.

Despite what the infomercials promise you, there are no ‘upper’ and ‘lower’ abs, by the way, so you can get rid of that idea. There’s just one big muscle in the front.

The obliques are diagonal muscles on the sides of the waist. They are mainly responsible for twisting and side bending movements. A good abdominal strengthening program should contain all three movements — spine rounding, twisting and side bending (not necessarily all in the same workout); more advanced practitioners should make ample use of multi-planar diagonal movements too.

The musculature of the trunk is crucial for stabilisation of the spine. For back safety and correct posture, core strength is very important.

The biceps are the muscles in the front part of the upper arm. They bend the elbow (flex the arm) and also turn the palms up (supinate the forearm). The triceps are opposite the biceps, and they straighten the elbow (extend the arm).

Here’s a list of the major muscle groups and some common exercises for each:

Exercises for legs and glutes

  • Squat

  • Leg Press

  • Step up

  • Lunge

  • Deadlift

Single joint movements for legs:

  • Knee extension

  • Hamstring curl

  • Calf raise

  • Dorsiflexion

  • Hip adduction/abduction

Waist exercises

  • Reverse curl up

  • Crunch

  • Twisting movements (crunch with a twist, standing tubing twists, etc.)

  • Deadlift

  • Back extension

  • Side bends, side crunches

Exercises for back muscles

  • Rows – bent over row, one arm DB row, machine row, cable row, etc.

  • Pulldown

  • Pullup

  • Reverse fly

Chest exercises

  • Barbell press

  • Dumbbell press

  • Machine press

  • Pushups

  • Dips

Single joint chest exercises: 

  • Pec deck

  • Dumbbell fly

  • Cable crossover

Shoulder exercises

  • Overhead press

  • Lateral raise

  • External rotation i.e. Hitch-hiker

Single joint exercises for arms:


  • Barbell curls

  • Dumbbell curl

  • Machine curl

  • Suspension curl (using rings or TRX)


  • Pressdown

  • Lying extension

  • Kickback

  • Overhead extension

  • Suspension tricep (using rings or TRX)