Exercise machine arm with single-handed adjustment

An exercise device, comprising:

• a resistance unit having a first connecting gear and a second connecting gear;
• and
• an arm being rotatable relative to the resistance unit about the first connecting gear, the arm having a central axis;
• wherein the arm mechanically disengages a locking mechanism from a third connecting gear;
• wherein the arm is activated by an activation force directed either along a length of the arm or about the central axis;
• wherein the activation force is mechanically converted into a linear force along the arm that disengages the locking mechanism from the third connecting gear;
• and
• wherein a lever is connected to a linkage that is connected to a second arm, wherein linkage is connected to the first connecting gear that is connected to the second connecting gear, the second connecting gear being connected to the second arm, wherein the lever is configured to be pressed down such that the lever rotates the linkage causing the second arm to rotate, and wherein the second arm is configured to rotate such that the second arm pulls out the locking mechanism that is engaged with the third connecting gear.