3. Overview of Major Muscle Groups

TL;DR: There are many muscle groups that are commonly talked about in the gym. This article overviews the appearance, location, function and training methods of the most common ones.

Intro

Traps, delts, pecs, lats and obliques. These are just a few of the many muscles groups you hear thrown around extensively, both in the gym and in online fitness communities. It certainly can take a fair amount of time to get them all straight in your head. Luckily, UpRiver is here to make it a little bit easier for you.

The aim of this article will aim to give a brief overview of the major muscles groups that are commonly talked about in the gym. A short description of the appearance and location of each muscle is given, along with that muscle’s main function and a few good exercises for training it.

If you are interested in a simple yet effective workout routine that hits all of these muscle groups with 5 basic exercises, please check out our article on Stronglifts here.

Traps

First on our list are the traps, short for their scientific name, the trapezius. The traps are a large pair of triangular shaped muscles, beginning in the middle of your back and extending upwards into the back of your neck and outwards towards the back of your shoulders. When trained, they give you notable looking wings extending down from your neck into your shoulders and a juicer looking upper back.

The primary function of the traps is to control movement of the scapula, which is the main bone in your shoulder. They can move your scapula when your spine is stabilized, and inversely they can move your spine when your scapula is stabilized [1]. In short, your traps control the movement of your shoulder.

Movements that involve raising your shoulders up towards your neck will engage your traps. Good exercises for training your traps include cleans, shrugs and farmer’s walks.

Delts

Next up, we have the delts, short for deltoids. The delts are the rounded muscles on the tops of your shoulders. Training your delts can give you big, boulder-looking shoulders.

The delts are responsible for moving your arm around your shoulder. They control the abduction (raising away from your body) of your arms, the internal and external rotation of your arms, as well as working in conjunction with your lats to extend your arm [2].

From left to right: Abduction, internal rotation and external rotation.

Good exercises to train your delts include overhead press, reverse flies and lateral raises.

Pecs

Now we have one of the more popular muscles: the pecs. The pecs, short for pectoral muscles, are the main muscles on your chest. They start just below your sternum and extend upwards into your armpit where they connect to your arm. Training them can give you a nice bulky chest that can really help you fill out a shirt.

The pecs function to adduct your arm, which is the reverse of the abduction that your delts are responsible for, ie bringing your arms back towards your body. They also work with your delts to control the internal rotation of your arm. [3] When your arm is stabilized, your pecs can be engaged to push your body up, such as when doing a pushup or a muscle-up

Interestingly, your pecs also play a minor role in breathing, as they work to pull your ribcage back, allowing room for air to fill your lungs.

Good exercises to train your pecs include bench press, push-ups and dips.

Lats

Next on our list we have the lats, which is short for Latissimus Dorsi. Your lats are large, flat muscles on your lower back, extending around to your sides and up to the bottom of your shoulders. They are partially covered by your traps. Training your lats will give you a broad, wide, strong looking back.

Your lats are primarily responsible for shoulder movement. They can adduct, extend and internally rotate your shoulder. [4] When your arms are fixed above your shoulder your lats can be engaged to lift your body, like when completing a pull-up.

Exercises for training lats include pull-ups, lat pull-downs and rows.

Abs

Next up we have the highly sought after, yet rarely achieved, abs. Abs, short for rectus abdominis, are the primary muscles in your core. They start in your groin and extend upwards to below your chest. Training your abs will help you obtain the coveted six-pack look.

Your abs work to flex your spinal column, bending your body as it draws your ribs closer to your pelvis. Your abs are also engaged when you bend your torso to the side. They also help to stabilize your body when you move your head, arms or legs.

Exercises that work the abs include planks, leg raises and crunches.

Hint: If you are really trying to get your abs to come through, consider checking out our article on If It Fits your Macros (IIFYM). It is arguably one of the best methods to reduce your body fat percentage so that you can get your abs to show through.

Obliques

Pairing closely with the abs, we next have the obliques. Your obliques start right above your hip and run up your side until right below your pecs. Training your obliques gives you aesthetic, muscular ridges up your side.

Your obliques have 3 main functions: bending your torso side to side, twisting your torso and helping to round your back, like during a sit-up [6]

Ways to train your obliques include side planks, medicine ball rotations and single arm versions of exercises, such as overhead press or bench press with a dumbbell.

Biceps

Now onto the holy grail of muscles: the bicep. Along with the tricep, your bicep (short for biceps brachii) is one of the two main muscles in your upper arm. It runs from your elbow to your shoulder on the inside of your arm. Training your biceps will give you big, bulky, bulging arms.

The primary function of your bicep is to move your forearm. It serves to both bend your elbow, bringing your forearm up to your arm (flexion) and to rotate your forearm outwards (supination) [7]. The bicep also plays a small role in assisting other muscles with the movement of the entire arm, such as helping your delts abduct your arm.

Bicep building exercises include curls and chin-ups.

Triceps

Next we have the slightly less popular, yet arguably more important counterpart to the bicep: the tricep. The tricep (short for triceps brachii) runs from your elbow to your shoulder on the back of your arm. Although often outshined by the bicep, your tricep actually makes up about 2/3rds of your upper arm [8], so when looking to obtain big arms it can be said to be more essential than then bicep. Training your triceps will give you wider arms and aesthetic horseshoe muscles on the backs of your arms.

Triceps primary function to extend your elbow joint, returning your arm from a bent position to a straight one. They also help to stabilize your shoulder, by keeping your humerus in the correct position in the shoulder joint. [9]

Triceps can be trained with cable pushdowns, skull crushers and diamond push-ups.

Glutes

Another very popular one on our list is the glutes. Your glutes (short for gluteus maximus) are, well, your ass muscles. Training your glutes will give you a lifted, firm, nicely shaped butt.

Your glutes primary function is to control hip action. They take care of thigh extension, thigh internal rotation, thigh external rotation as well as thigh abduction and adduction [10]. The glutes also play key roles for body stability, both assisting us in standing upright and standing up from a seated position.

Good exercises to train glutes include squats, step-ups and good mornings.

Quads

Getting into the legs now we have the quads. Your quads, short for quadriceps, are a large group located in your thigh, extending from just below your knee up to your hips on the front of your legs. Training your quads will give you big, bulky, powerful looking legs.

Your quads main role is to control movement of the lower leg around the knee. You quads work primarily to extend (straighten) the knee, but also assist your hamstrings in the flexion (bending) of the knee. Additionally, your quads play an important role in stabilizing your patella (knee-bone), keeping it in the right position and preventing it from being dislocated during extension [11]

Exercises to build quads include squats, leg extensions and lunges.

Hamstrings

Next on our list we have the hamstrings. Much like your quads, your hamstrings are another large group of leg muscles running from just below the knee up to your glutes on the back of your legs. Training your hamstrings will give you powerful, explosive legs, good for sprinting, jumping and other fast movements.

Hamstrings work both on your hips and on your knees. When your legs are kept fixed, your hamstrings assist with hip flexion. This is most powerful in returning your torso from bent over to upright. When acting on your knee, the hamstrings play the primary role in flexion (bending) of the leg. Furthermore, your hamstrings help to stabilize your pelvis, giving them an important role during walking or running.

Workouts for stronger hamstrings include deadlifts, good mornings and hamstring curls.

Calves

Lastly, but not least, we have the elusive calves. Many gym-goers claim that this one is the hardest to add size to. The calf muscles (scientific names gastrocnemius and soleus) run from the ball of your foot up to your knee on the back of your legs. Training your calves will give you fuller, more balanced looking legs, along with a nice muscular bulge just below your knee.

Your calves function both to move your foot and your knee. They team up with your hamstrings to bend your knee and they are responsible for essentially all movement of the foot. They play vital roles in allowing us to walk, run and jump [13].

Good calf training exercises include calf raises, jump rope and jump squats.

Conclusion

There you have it: 12 of the most common muscle groups that you’ll hear thrown around in the gym. For many, this was likely a very basic overview of things you already knew, yet hopefully for some it helped clear up some of the confusion of the terms they’ve been hearing.

Now that you know where each muscle group is and what it does, try to keep it in mind when you make a movement. For example, when you bend over to pick up something off the ground, think about how your hamstrings, quads, glutes and abs are being used to make the movement. This will help to improve your mind-muscle connection (discussed here (LINK)) which will, in turn, improve your progress in the gym.