When you step into the weight room at AFAC gym, you’re greeted with a range of bench press setups—flat, incline, decline, dumbbells, barbells. But lifters frequently return to one common debate: which is better for building chest strength and size — incline or flat bench press?

While both variations of the bench press are foundational strength exercises targeting the upper body, they aren’t interchangeable. Each one brings its own benefits, challenges, and ideal use cases. In this blog, we’ll break down the differences between incline and flat bench presses, how they work your muscles, and how to choose the right one for your training goals.

What Muscles Do Bench Presses at the Gym Work?

The bench press is one of the most popular compound lifts in the gym, targeting a collection of powerful muscles across the upper body. While the emphasis may shift slightly depending on the variation (flat, incline, decline, barbell, dumbbell, etc.), all forms of the bench press engage three major muscle groups.

1. Pectoralis Major and Minor

The primary movers in a bench press are the chest muscles, especially the pectoralis major. This thick, fan-shaped muscle covers much of the chest and is responsible for horizontal adduction, moving your arms toward the center of your body.

Beneath it lies the pectoralis minor, a smaller yet essential muscle that helps stabilize your scapula during pressing motions. Together, these muscles, also known as “pecs,” generate the bulk of the power required for a successful bench press rep.

2. Anterior Deltoids

Located at the front of your shoulders, the anterior deltoids assist in moving your arms forward. Although they’re secondary to the chest during a press, they become especially important in the final phase of the lift. When the bar moves past the midpoint, the shoulders kick in to help lock it out.

It’s important to maintain good form here — if your shoulders lift off the bench or move too far forward, they may absorb too much of the load, reducing chest activation and increasing injury risk.

3. Triceps Brachii

This three-headed muscle on the back of the upper arm contributes significantly during the lockout phase of a press. As your elbows extend and straighten the arms, the triceps generate the force needed to complete the movement.

What Secondary Muscles Are Involved?

Beyond the primary movers, several supporting muscles assist with stability and control throughout the lift. These secondary muscles don’t necessarily drive the motion, but they ensure smooth execution and injury prevention.

Biceps Brachii

Although biceps are more known for pulling exercises, they play a stabilizing role in the bench press. They help keep the upper arm bone secure within the shoulder joint and support the elbow’s positioning.

Serratus Anterior

Situated on the side of the ribcage, the serratus anterior is heavily involved in shoulder blade movement. A strong serratus helps you drive the barbell upward with more efficiency, particularly in the finishing range of motion.

Trapezius and Rhomboids

These upper back muscles help pull the shoulder blades together and down. This retraction creates a solid base on the bench and enhances stability throughout the lift. A weak upper back can lead to power leaks and inefficient force transfer.

Core Muscles

Even though you’re lying down, your core plays a critical role in maintaining full-body tension. A strong core prevents excess movement and helps keep your torso rigid, allowing you to press more weight safely. Core-focused movements like Pallof presses and farmer’s carries can enhance your bench performance by training breath control and midline stability.

Incline Barbell Bench Presses

The incline barbell bench press is a variation that shifts the angle of the bench to about 15–30 degrees. This slight upward tilt has a significant impact on muscle activation.

Benefits

• Targets the Upper Chest: The incline position isolates the clavicular head of the pectoralis major (upper pecs), which is often underdeveloped in comparison to the mid and lower chest.
• Shoulder Emphasis: This movement activates the front deltoids more than the flat bench press, making it a hybrid between a chest and shoulder exercise.
• Rotator Cuff-Friendly: Due to the angle, there may be less strain on the rotator cuff, which is helpful for individuals recovering from shoulder issues.

Drawbacks

• Limited Overall Chest Development: Because the focus is shifted to the upper pecs and shoulders, incline pressing doesn’t activate the full chest as thoroughly as the flat bench.
• Overtraining Risk: Since the shoulders are more involved, you need to avoid training deltoids too soon afterward. Overlapping muscle groups can lead to fatigue or injury.

How to Do the Incline Bench Press

1. Set the Bench: Adjust the bench to a 15–30 degree incline. Too steep will shift the focus too much onto the shoulders.
2. Grip the Bar: Lie back with your eyes directly under the bar. Use a grip slightly wider than shoulder-width.
3. Unrack with Control: Unrack the bar and bring it directly over your shoulders.
4. Lower Slowly: Bring the bar down to your upper chest, just below the collarbone. Elbows should angle about 45 degrees from your torso.
5. Drive Up: Press the bar back up in a straight line, focusing on contracting the upper chest. Repeat for the desired amount of reps and sets.

Flat Barbell Bench Presses

Flat barbell bench pressing is the classic version of this lift and is widely used to build size and strength across the entire chest.

Benefits

• Even Activation: Both the upper and lower pec fibers are engaged evenly, making this a solid choice for comprehensive chest development.
• Natural Movement Pattern: This motion closely mimics pushing activities you might do outside the gym.

Drawbacks

• Higher Risk for Shoulder Issues: The flat bench puts the pec tendon in a more vulnerable position, especially when the lift is done poor form or excessive weight.
• Deltoid Dominance: Many lifters unintentionally overuse their front delts, reducing chest emphasis and increasing injury risk.

Common Mistakes

• No spotter for heavy lifts
• Uneven grip or bar tilt
• Letting one side dominate the press
• Skipping warm-up and mobility work

Proper preparation — including stretching, resistance band work, and mobility drills — can make a world of difference.

How to Do the Flat Bench Press

1. Position Yourself: Lie flat on the bench with your feet firmly planted and shoulder blades retracted. Load the barbell with the desired amount of weight.
2. Grip the Bar: Grab the bar with a slightly wider-than-shoulder-width grip. Keep wrists straight.
3. Unrack the Bar: Bring the bar over your mid-chest area.
4. Controlled Descent: Lower the bar until it touches your sternum. Avoid bouncing or flaring elbows out wide.
5. Push and Lockout: Press the bar straight up while keeping your core engaged and feet rooted to the floor.

Incline vs. Flat Bench Press: Which Is Best?

So which press should take priority in your workout routine? It depends on your goals.

If Your Goal is Overall Chest Development

The flat bench press reigns supreme for building general size and strength. Studies show it activates the mid and lower pecs more thoroughly than other angles. It’s also a great starting point for beginners due to its straightforward mechanics.

If You Want Upper Chest Emphasis

The incline bench is your friend. Muscle activation research suggests that a 30-degree incline is ideal for isolating the upper pecs while still engaging the shoulders. Just be mindful not to make the incline too steep, or you’ll shift the effort away from the chest.

Many gym-goers at AFAC incorporate both variations into their weekly routines to ensure balanced development across all regions of the chest. That’s often the best approach.

Press Your Way to Progress at AFAC

Whether you’re pushing the bar on a flat bench or an incline, both exercises offer major gains when performed with proper form and intent. Think of the flat bench as your bread and butter — it builds bulk and strength across your entire chest. The incline press? That’s your sculpting tool, chiseling out the upper pecs for a more complete, powerful look.

At AFAC gym, our equipment and expert staff are here to help you perfect your technique, avoid injury, and get the most out of your training sessions. So next time you’re choosing a bench, consider your goals, trust your form, and press on with confidence.

We hope you’ll visit AFAC gym today to speak to our team about our affordable memberships. AFAC gym is committed to supporting your health and wellness efforts, so you’ll see the results you’re working so hard for. That’s why we were voted the best gym in Thornton, Colorado, and have hundreds of 5-star reviews.

To learn more about our top-rated gym and our incredible array of strength training and cardio equipment — as well as our unique offerings and amenities like daily group classes, cryotherapy, InBody 770 assessments, hydro massage, personal trainers, and our rock climbing wall and cave — we hope you will contact us or visit for a personalized tour. Our team will be happy to help you. For more information and assistance, you can also contact our gym owner, Susan, at 720-849-0245 or susan@adventurefitness.club.