The aims of this study were firstly to compare the similarity in upper-body muscle activation between the bench press and push-up at similar loads, and secondly to establish a 1-RM prediction equation between the two exercises based upon the load-velocity relationship. Twenty resistance-trained male athletes (age 22.5 ± 5.24 years, body mass 83.7 ± 10.7 kg, body height 1.80 ± 0.06 m) performed push-ups and bench presses with four different loads. Push-ups were performed without a weight vest and with a 10-20-30 kg weight vest. Bench presses were performed at 50-80% of athletes' assumed 1 repetition max (1-RM) in 10 kg steps, while a linear encoder measured performance during the exercises. A load-velocity relationship was established as a product of the load and velocity for the push-up and bench press per participant and the equation was used to establish a predicted 1-RM. Mean muscle activation of eight upper body muscles was recorded for each exercise and each load. The main findings of this study demonstrate an extremely large association between the predicted 1-RM loads performed with the push-up and bench press (r = 0.93) in experienced resistance trained men. Furthermore, most muscles showed similar activations between the two exercises with the different loads except the deltoid and biceps brachii muscles. It may be concluded that it is possible to predict a cross-over 1-RM between the two exercises based upon the load-velocity relationship in each exercise, and that training push-ups largely targets the same muscles as the bench press except the deltoid and biceps muscles. For coaches and athletes, the use of this method is a low cost and time-effective alternative for standard 1-RM bench press testing to predict maximal upper body strength.