Interactive Muscle Anatomy
Click a muscle to see its location, function, and exercises.
How to use this muscle map
Click the muscle you want to train on the front or back figure. You'll see its location and function, plus a list of Planfit exercises that target it. Tap any exercise to open its step-by-step guide and video.
Major muscle groups and their function
| Muscle | Function |
|---|---|
| Chest (Pectorals) | Pulls the arms toward the front of the body and powers pushing movements. It's the prime mover in exercises like the bench press and push-up. |
| Lats (Latissimus Dorsi) | Pulls the arms down and back. It's the largest back muscle and builds the wide V-taper, trained with pull-ups, lat pulldowns, and rows. |
| Traps (Trapezius) | Shrugs the shoulders and draws the shoulder blades together and down. Spanning the neck and upper back, it's trained with shrugs, upright rows, and deadlifts. |
| Lower Back (Erector Spinae) | Keeps the spine upright and extends the torso. It's key to good posture and a stable lower back, trained with deadlifts and back extensions. |
| Shoulders (Deltoids) | Raises the arms to the front, side, and back. Trained with overhead presses and raises, it builds the rounded look of the upper body. |
| Biceps | Bends the elbow to lift weight. It's the prime mover in curls and gives the front of the arm its size. |
| Triceps | Straightens the elbow. It makes up about two-thirds of the upper arm, so it's key to building bigger arms. |
| Forearms | Moves the wrist and fingers and produces grip strength. It matters for holding heavy weights longer. |
| Abs | Bends the torso forward and stabilizes the trunk. As the center of core strength, it's involved in nearly every exercise. |
| Obliques | Twists the torso and bends it sideways. These side muscles are key for rotation and a stable lower back. |
| Quadriceps | Straightens the knee. It's the prime mover in squats and lunges and one of the largest muscle groups in the lower body. |
| Hamstrings | Bends the knee and extends the hip. Trained with deadlifts and leg curls, it's key to running and jumping power. |
| Glutes | Extends the hip and stabilizes the pelvis. One of the strongest muscles in the body, trained with hip thrusts and squats. |
| Calves | Points the toes to power walking, running, and jumping. Trained with calf raises. |
Exercises by muscle group
Chest (Pectorals)
Lats (Latissimus Dorsi)
Traps (Trapezius)
Lower Back (Erector Spinae)
Shoulders (Deltoids)
Biceps
Triceps
Forearms
Abs
Obliques
Quadriceps
Hamstrings
Glutes
Calves
FAQ
What's the difference between primary and secondary muscles?
The primary mover produces most of the force in a movement, while secondary (assisting) muscles help out. In the bench press, for example, the chest is primary and the triceps and shoulders are secondary. Each exercise page shows its target muscles.
How often should I train each muscle per week?
Most research suggests training each muscle about twice a week. Spreading volume across 2–3 sessions tends to beat doing it all at once for growth and recovery. Give the same muscle roughly 48 hours of rest.
Can I change the shape of a muscle with exercise?
A muscle's basic shape (its length and attachment points) is set by genetics and can't be changed. But you can grow its size and develop the different heads of a muscle group evenly, which does change your overall silhouette.
Which muscles should a beginner start with?
Beginners should start with compound movements that work big muscle groups (chest, back, legs). They train several muscles at once, so they're efficient. The Planfit app builds which muscles to train, and in what order, around your goal and experience.