Background <p>TRX suspension push-ups enable adjustment of body angle to manipulate loading and neuromuscular demand. However, the effects of extreme inclinations, particularly declined positions where the hands are lower than the feet, on upper-body muscle activation remain unclear. This study aimed to examine how different body angles influence upper-body activation during TRX push-ups compared with those performed on a stable surface.</p> Methods <p>Nineteen trained men performed push-ups at five body angles (+ 30°, + 15°, 0°, − 15°, − 30°) under TRX and stable-surface conditions. Surface EMG was recorded from the pectoralis major (PM), anterior deltoid (AD), triceps brachii (TRI), upper trapezius (UT), and serratus anterior (SA). EMG data were normalized to maximal voluntary isometric contraction (%MVIC), and two-way repeated-measures ANOVA was used to compare activation differences between conditions and angles. The significance level was determined as <i>p</i> &lt; .05.</p> Results <p>TRX push-ups elicited medium to extremely high activation in the PM, AD, and TRI. PM activation was significantly greater with TRX compared with stable-surface push-ups (<i>p</i> &lt; .05), particularly at + 30°, + 15°, and 0° compared with lower angles (<i>p</i> &lt; .05). Both TRX and stable-surface push-ups produced greater AD, TRI, UT, and SA activation at − 30° than at higher angles.</p> Conclusion <p>TRX push-ups at higher inclinations (+ 30° to 0°) effectively target the pectoralis major, while lower angles (− 30°) preferentially increase activation of the anterior deltoid, triceps brachii, upper trapezius, and serratus anterior. These findings provide angle-specific recommendations for suspension training push-ups to optimize muscle activation patterns.</p>