Single-Arm Overhead Press

Move · Resistance Training · Movement, Typed Supps

The hardest part for your waist is the bottom of the press, not the top.

Stage by stage

Set-up (Load offset from midline): A weight racked at one shoulder applies a frontal-plane moment at the spine equal to the load times its distance from the midline.
Early in the press (Side of waist works): The contralateral obliques and quadratus lumborum work hardest here, where the weight sits furthest from the spine.
Toward lockout (Scapula rotates freely): The load moves in over the midline, reducing the trunk demand, while the unconstrained scapula lets the humerus find a path a barbell would not allow.
Months later (Shoulder strength and trunk control): Deltoid strength progresses normally while trunk stability carries over to other offset loading, at the cost of lower total load per session.

Muscles trained

Primary: shoulders
Secondary: abs, obliques, rotator cuff, triceps

Intensity

5 METs (Resistance (weight) training, squats, slow or explosive effort).

Time to effect

Weeks: The obliques and deep core muscles are often surprisingly sore after the first sessions, a sign of how much anti-lateral-flexion work the single-arm version demands.
Months: Shoulder strength climbs similarly to a standard overhead press, while the core stability built alongside it tends to carry over well to other single-sided or asymmetric lifting.

Related supplements

Creatine Monohydrate

Common myth

"Single-arm pressing is just half the weight of a two-arm press, done twice." In reality: Most people cannot press half their two-arm overhead press weight for reps on one side — the loss of a stable, symmetric base makes the single-arm version disproportionately harder.