Strength exercise mechanisms

A treadmill, comprising:

• a frame including a first post and a second post;
• an exercise deck attached to the frame;
• a plurality of first catches incorporated into the first post on a rearward side of the first post extending toward a majority the exercise deck;
• a plurality of second catches incorporated into the second post on a rearward side of the second post extending toward the majority the exercise deck;
• and
• a push-up bar connected to the frame on the rearward side of the first post and the rearward side of the second post so that a user performs a pushup while on the exercise deck, the push-up bar being elevated over the exercise deck, wherein the push-up bar is configured to removably rest on top of one of the plurality of first catches at a first end and one of the plurality of second catches at a second end, wherein the position of the push-up bar is adjustable depending on which of the plurality of first catches and which of the plurality of second catches are selected.