Bench Press Incline, Decline and Flat – Do They Really Work?

During my undergraduate degree I was required to write a thesis on an area of interest in sports science. One area that is of interest to most male gym members is the infamous bench press; thus it was my decision to examine the effect different inclinations of bench press has on the major chest muscle – the pectoralis major. Understanding exactly what you are training and the benefits associated with specific movement patterns and muscle activations are key to success in both performance and rehabilitation and training for people serious about resistance training.

The aim of my study was to analyse and examine the connection between motor unit recruitment within the two portions of the pectoralis major and three inclinations of the bench press exercise. Eight healthy male subjects (N = 8), volunteered to participate in the study (Mean ± SD: age 21.75 ± 0.89, weight 75.9 ± 5.5 kg). Each subject completed 3 repetitions on incline (+30º from horizontal), decline (-15º from horizontal) and horizontal bench press at 70% of their predetermined one repetition maximum (1-RM). Electrodes were placed over the clavicular head and sternocostal head of the pectoralis major. Surface electromyography was recorded and smoothed to calculate the root mean squared (RMS). The results were analysed using repeated-measures ANOVA and tested for significance (p < 0.05). The results showed significantly greater activation of the sternocostal head (lower chest) during decline bench press compared to flat bench press. Furthermore, the clavicular head (upper chest) was significantly active during incline bench press when compared to horizontal, but less active during the decline bench press.

In conclusion there are variations in motor unit recruitment in the sternocostal head of pectoralis major during decline bench presses, and the clavicular head during the incline bench press. So, after all it is worth spending time isolating different movements to work on specific muscles. Understanding activation levels for conditioning movements and the effects of producing such movements within a different body orientation may have value for the strength and conditioning professional and the average gym attendee in training programme and design.