084 - Bench Press vs. Dumbbell Flyes: Targeted Muscle Activation and Tactical Programming
Upper-body training often centers on bench presses and chest fly variations, but few practitioners critically compare these staples under objective neuromuscular analysis. This study provides detailed surface EMG data comparing barbell bench press (BBP) and dumbbell flyes (DF) across multiple muscle groups, motion phases, and resistance-trained male subjects.
For tactical strength professionals and rehab providers, understanding these biomechanical and neuromuscular nuances matters, especially when time, recovery bandwidth, and mission-specific adaptations dictate precision in programming.
What They Found:
Seventeen trained males performed both BBP and DF at their 6-repetition maximum (6RM), while researchers measured EMG activity in the pectoralis major, anterior deltoids, triceps brachii, and biceps brachii.
The researchers analyzed not only whole-rep EMG data but also broke down each fifth repetition into six distinct movement phases (descending and ascending, split into upper, middle, and lower thirds).
Key findings included:
Pectoralis major: BBP elicited greater activation (16% higher overall) than DF. Significant increases in EMG were found in all descending phases and the upper ascending phase.
Anterior deltoid: BBP showed 25% greater overall activation, with the highest spikes in the upper and middle phases of the lift.
Triceps brachii: BBP activated the triceps up to 84% more than DF across nearly every movement phase.
Biceps brachii: DF outperformed BBP significantly—76% higher overall, with substantial activation in all phases, especially due to the DF’s stabilization demands.
Also noteworthy: total time under tension was shorter for BBP (18.7s) versus DF (23.5s), and the total 6RM load was more than double for BBP (~88.5kg vs. 40.5kg).
What This Means:
The barbell bench press is a superior compound movement for stimulating the primary pushing muscles: pectoralis major, anterior deltoid, and triceps brachii, especially under higher mechanical loads. Its consistent moment arm throughout the range of motion contributes to elevated activation. In contrast, the dumbbell fly requires greater stabilization through the shoulder joint, driving up biceps brachii involvement, which may be useful in prehabilitation or isolated motor control training.
These findings support prioritizing BBP for hypertrophy and pressing strength, but they also validate DF as a valuable secondary tool, especially when targeting horizontal shoulder flexion with extended elbows or for joint stabilization under load.
Tactical Implications:
Prioritize BBP for maximal output: Higher loads, more consistent muscle activation across all prime movers.
Use DF for stabilizer and accessory focus: Especially useful for biceps, joint control, and shoulder-centric applications in low-load rehab or high-precision drills.
Adjust based on time under tension: DF takes longer per set; valuable for hypertrophy or control, but taxing in compressed programming windows.
Leverage joint mechanics for specific goals: The DF changes the moment arm more dramatically throughout ROM; ideal for increasing load in stretched positions or targeting end-range motor control.
Cycle both into long-term programming: Use BBP as the foundational push, with DF as a de-load, isolation, or activation primer.
Questions To Consider:
Are you choosing your chest exercises based on biomechanics or tradition?
How often do you factor moment arm shifts and joint stabilization into program design?
Could the flye’s greater biceps activation benefit athletes requiring fine motor control under load?
How might DF-based volume work complement BBP intensity work in tactical mesocycles?
Are your exercise progressions considering elbow integrity, shoulder stability, and phase-specific activation?
Solstad TE, Andersen V, Shaw M, Hoel EM, Vonheim A, Saeterbakken AH. A Comparison of Muscle Activation between Barbell Bench Press and Dumbbell Flyes in Resistance-Trained Males. J Sports Sci Med. 2020;19(4):645-651. Published 2020 Nov 19.