Flat Dumbbell Bench Press vs Incline Dumbbell Bench Press: Which One Will Grow More Chest Muscle for You?

Building a well-developed chest is a primary goal for many lifters, whether they are beginners or seasoned gym-goers.

Among the various exercises targeting the chest, the flat dumbbell bench press and incline dumbbell bench press are two of the most popular. Both exercises are staples in most chest routines, but which one is more effective for growing your chest muscles? In this article, we’ll delve into the science behind these exercises, compare their effectiveness, and help you determine which one might be better suited to your goals.

Understanding Chest Anatomy

Before comparing the flat and incline dumbbell bench presses, it’s essential to understand the anatomy of the chest muscles. The chest primarily consists of the pectoralis major and pectoralis minor muscles.

Pectoralis Major

The pectoralis major is the larger of the two chest muscles and is divided into two heads:

• Clavicular head (upper chest): This portion originates from the clavicle (collarbone) and is targeted more effectively by incline pressing movements.
• Sternal head (middle and lower chest): This portion originates from the sternum (breastbone) and is primarily worked during flat pressing movements.

Pectoralis Minor

The pectoralis minor is a smaller muscle that lies beneath the pectoralis major. While it plays a role in shoulder movement and stability, it is not the primary focus in chest exercises.

Flat Dumbbell Bench Press: Overview and Benefits

The flat dumbbell bench press is a horizontal pressing movement performed on a flat bench. This exercise is considered a compound movement because it engages multiple muscle groups, including the pectorals, triceps, and anterior deltoids (front shoulders).

Benefits of the Flat Dumbbell Bench Press

• Maximal Chest Activation: The flat dumbbell bench press primarily targets the sternal head of the pectoralis major, making it an excellent exercise for overall chest development.
• Balanced Development: Dumbbells allow for a greater range of motion compared to a barbell, and they also help in correcting muscle imbalances since each arm works independently.
• Joint-Friendly: The natural movement path of dumbbells can be more forgiving on the shoulders compared to a barbell, reducing the risk of injury.

Incline Dumbbell Bench Press: Overview and Benefits

The incline dumbbell bench press is performed on a bench set at an incline, typically between 15 to 45 degrees. This angle shifts the focus from the middle and lower chest to the upper chest (clavicular head of the pectoralis major).

Benefits of the Incline Dumbbell Bench Press

• Upper Chest Emphasis: The incline dumbbell bench press is one of the best exercises for targeting the upper portion of the chest, which can often lag in development compared to the middle and lower chest.
• Shoulder Engagement: This exercise also engages the anterior deltoids more significantly than the flat bench press, contributing to overall shoulder development.
• Variety in Chest Training: Incorporating the incline press adds variety to your chest workout, helping to ensure balanced chest development.

Muscle Activation: What Does the Science Say?

To determine which exercise is more effective for chest development, it’s important to examine muscle activation studies.

EMG Studies on Chest Activation

Electromyography (EMG) studies measure the electrical activity produced by muscles during exercise, providing insights into how effectively different exercises activate specific muscle groups.

• Flat vs Incline Bench Press: A study by Barnett, Kippers, and Turner (1995) compared EMG activity in the pectoralis major during the flat and incline bench press. The study found that the flat bench press elicited greater activation in the sternal head of the pectoralis major, while the incline bench press showed higher activation in the clavicular head .
• Dumbbells vs Barbell: Another study by Trebs, Brandenburg, and Pitney (2010) compared muscle activation during dumbbell and barbell bench presses. The researchers concluded that dumbbells activated the pectoral muscles more effectively than the barbell, likely due to the greater range of motion and increased stabilization requirements .

These findings suggest that both the flat and incline dumbbell bench presses are effective for chest development, but they target different portions of the pectoralis major.

Hypertrophy and Training Volume

Hypertrophy, or muscle growth, is largely determined by training volume (sets × reps × weight). To maximise hypertrophy, it’s crucial to engage all parts of the pectoralis major effectively.

Flat Bench Press for Mass

The flat dumbbell bench press allows for heavier loads compared to the incline version, which can lead to greater overall chest activation. Heavier loads generally contribute to greater mechanical tension, one of the primary drivers of hypertrophy .

Incline Bench Press for Balanced Development

While the incline dumbbell bench press may not allow for as heavy loads as the flat version, it is indispensable for developing the upper chest. Neglecting the upper chest can lead to an imbalanced appearance and may hinder overall chest growth. Studies suggest that including incline presses in your routine can lead to more symmetrical and aesthetically pleasing chest development .

Strength Gains: How Do They Compare?

Strength gains are another critical factor to consider. While both exercises contribute to overall strength, they do so in slightly different ways.

Flat Dumbbell Bench Press for Strength

Because the flat dumbbell bench press typically allows for heavier weights, it is often favoured in strength-building programs. The ability to press more weight can lead to greater overall strength gains, especially in the pectoral muscles and triceps .

Incline Dumbbell Bench Press for Functional Strength

The incline dumbbell bench press, while generally performed with lighter weights, improves functional strength by engaging the upper chest and shoulders. This exercise mimics many real-life movements, such as pushing objects overhead, making it highly functional for everyday activities .

Range of Motion and Muscle Stretch

The range of motion (ROM) and the degree of muscle stretch during an exercise are important for muscle hypertrophy. Greater ROM and muscle stretch have been shown to increase muscle activation and growth.

Flat Dumbbell Bench Press

The flat dumbbell bench press typically offers a larger ROM for the sternal head of the pectoralis major. The horizontal position allows for a deep stretch of the chest muscles at the bottom of the movement, which can contribute to greater muscle hypertrophy .

Incline Dumbbell Bench Press

The incline dumbbell bench press, on the other hand, provides a greater stretch for the clavicular head of the pectoralis major. This increased stretch, combined with the upward angle, ensures effective activation of the upper chest.

Injury Risk and Joint Health

When comparing exercises, it’s also important to consider injury risk and joint health, especially for those with pre-existing conditions or those training at high intensities.

Flat Dumbbell Bench Press

The flat dumbbell bench press is generally considered safe, but like all exercises, it can pose risks if performed incorrectly. Common issues include shoulder impingement, particularly if the lifter lowers the dumbbells too far, placing undue stress on the shoulder joints .

Incline Dumbbell Bench Press

The incline dumbbell bench press, while excellent for upper chest development, can also increase the risk of shoulder strain, particularly if the bench is set at too steep an angle. An incline of 30 to 45 degrees is generally recommended to minimise this risk while still effectively targeting the upper chest .

Programming: How to Incorporate Both Exercises

To achieve optimal chest development, it’s wise to incorporate both the flat and incline dumbbell bench presses into your routine. Here’s how you can do it:

Sample Chest Workout

1. Warm-Up:
   • Light cardio (5 minutes)
   • Dynamic stretching (focus on shoulders and chest)
2. Flat Dumbbell Bench Press:
   • 4 sets of 8-12 reps
   • Focus on a controlled eccentric (lowering phase) and a powerful concentric (lifting phase)
3. Incline Dumbbell Bench Press:
   • 4 sets of 8-12 reps
   • Ensure the bench is set at an appropriate angle (30 to 45 degrees)
4. Accessory Movements:
   • Dumbbell Flyes (flat or incline): 3 sets of 12-15 reps
   • Push-Ups or Cable Crossovers: 3 sets of 15-20 reps
5. Cool-Down:
   • Static stretching (focus on chest and shoulders)
   • Foam rolling

Key Considerations for Optimal Results

When choosing between the flat and incline dumbbell bench presses, consider the following factors:

Your Training Goals

• If your primary goal is to increase overall chest size and strength, prioritise the flat dumbbell bench press.
• If you’re aiming for balanced chest development and want to emphasise the upper chest, make the incline dumbbell bench press a staple in your routine.

Training Experience

• Beginners may benefit more from focusing on the flat dumbbell bench press initially, as it builds a strong foundation for chest development.
• Intermediate and advanced lifters should incorporate both exercises to ensure comprehensive chest development.

Frequency and Volume

• Incorporate both exercises into your weekly routine, ideally on different days, to prevent overtraining and ensure adequate recovery.
• Adjust the volume (sets and reps) based on your overall training program and goals.

Conclusion: Which One Will Grow More Chest Muscle for You?

Both the flat and incline dumbbell bench presses are highly effective for chest development, but they target different areas of the pectoralis major. The flat dumbbell bench press is superior for overall chest mass and strength, particularly in the middle and lower chest. In contrast, the incline dumbbell bench press is unmatched in its ability to develop the upper chest, contributing to a more balanced and aesthetically pleasing physique.

For the best results, incorporate both exercises into your routine, tailoring the frequency and volume to your specific goals. By doing so, you’ll ensure comprehensive chest development and maximise your muscle growth potential.

References

Barnett, C., Kippers, V., & Turner, P. (1995) ‘Effects of variations of the bench press exercise on the EMG activity of five shoulder muscles’, Journal of Strength and Conditioning Research, 9(4), pp. 222-227.

Trebs, A.A., Brandenburg, J.P., & Pitney, W.A. (2010) ‘An electromyographic analysis of 3 muscles surrounding the shoulder joint during the performance of a chest press exercise at several angles’, Journal of Strength and Conditioning Research, 24(7), pp. 1925-1930.

Schoenfeld, B.J. (2010) ‘The mechanisms of muscle hypertrophy and their application to resistance training’, Journal of Strength and Conditioning Research, 24(10), pp. 2857-2872.

Welsch, E.A., Bird, M., & Mayhew, J.L. (2005) ‘Electromyographic activity of the pectoralis major and anterior deltoid muscles during three upper-body lifts’, Journal of Strength and Conditioning Research, 19(3), pp. 449-452.

Key Takeaways