Should we bench press with an arched back? Here’s what the research says

• 15 participants with endurance experience (mostly powerlifting athletes), 13 men and 2 women, took part in the study.
• They visited the lab for three separate training sessions. During the first two sessions, they performed a one-repetition maximum (1RM) test using the flat or arched back bench press.
• Each participant completed two warm-up sets before the 1RM test. The 1RM test involved performing sets of a single repetition with increasing weight until failure. Each set was separated by three minutes of rest.
• After testing 1RM for both techniques, participants performed bench press sets at 50%, 70%, and 90% of their 1RM using both the flat back and arched back techniques. This resulted in a total of six games per participant.
• The flat back technique required five points of contact with the bench: head, shoulder blades, thoracic trunk, buttocks and feet, without arching the lower back. The arched back technique involved arching the lower back as much as possible while maintaining the same contact points.
• Statistics were analyzed after collecting results using EMG (electromyography) to compare the differences between flat back and arched back techniques for several parameters including: 1RM, bar displacement (bar movement), velocity , power and muscle activation.

• The arched back bench press technique resulted in a greater 1RM compared to the flat back technique.
• The flat back technique resulted in greater bar displacement at all loads tested.
• The flat back bench press technique showed higher bar speed at 50% 1RM.
• No significant differences in power were observed between the two techniques in all weights.
• There were no significant differences in the activation of the upper and lower pec muscles between the flat back and arched back techniques.
• There was a tendency for increased triceps activation with the arched back technique.

The study concluded that flat-back and arched-back bench press techniques have their advantages depending on training goals. The arched back technique allows for a larger 1RM, likely due to the reduced range of motion, making it suitable for situations where lifting heavier loads is the primary goal such as powerlifting.

However, the flat back technique showed higher bar speed at lighter loads, which may be beneficial for improving explosive strength. Both techniques elicited similar muscle activation of the pectoral muscles, while the arched back technique showed a trend toward greater activation of the triceps.

The results suggest that incorporating flat-back and arched-back bench press techniques into training programs can provide a well-rounded approach to developing upper body strength and power.

We can choose between the two techniques based on our goals and training preferences. For example, along with this study, more evidence suggests that those who participate in powerlifting competitions may arch their back more to achieve a higher number.

However, an increased stretch in the chest and improved range of motion could result in more muscle gain. So if your goals are to gain more muscle mass, perhaps less arch would be more appropriate.

To get the best of both worlds, you can arch your back a little, for example, not as steeply as the powerlifting technique, keeping your trunk closed and stable and getting as much stretch as possible through your pecs with elbows nice and low. This can also help reduce pressure on the shoulder joints. In short, choose the technique that feels right for your body, from which you get the best results, according to your training goals.

If you want to read more about the science cited in this article, here are the references: