The Claim

In the 45° inclined bench press exercise, electromyographic analysis reveals significantly greater activation (normalized RMS amplitude) of the clavicular head of the pectoralis major compared to the sternocostal head (P < 0.001). Conversely, during the flat bench press, the sternocostal head shows significantly greater activation compared to the clavicular head (P < 0.001).

Source: Non-uniform excitation of pectoralis major induced by changes in bench press inclination leads to uneven variations in the cross-sectional area measured by panoramic ultrasonography

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
26score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

Quantitative
1 study reviewed
In plain English

When you do bench press on an incline, the upper part of your chest works harder. But when you do flat bench press, the middle-lower part of your chest works harder instead. Scientists measured this using muscle activity recordings.

See the scientific wording

During 45° inclined bench press, the clavicular head of pectoralis major demonstrates significantly greater muscle activation (normalized RMS amplitude) compared to the sternocostal head (P < 0.001), while flat bench press produces the opposite pattern with greater sternocostal activation (P < 0.001)

What the research says

1 study

  1. Study: Non-uniform excitation of pectoralis major induced by changes in bench press inclination leads to uneven variations in the cross-sectional area measured by panoramic ultrasonography

    The study directly confirms what the claim says: when doing incline bench press at 45 degrees, the upper chest (clavicular head) works harder than the lower chest (sternocostal head), and when doing flat bench press, the lower chest works harder than the upper chest - both with strong statistical significance (P < 0.001).

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

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