Which of the following exercises is NOT used to increase muscular strength?

This is a nonstop, repetitive exercise that raises your heart rate and breathing gradually.

This is an intense activity that lasts only a short time because the heart and lungs cannot keep up with the demand of oxygen.

An activity that involves contraction and relaxation of muscles resulting in a movement.

An activity that involves contraction of muscles resulting in NO movement.

An activity that involves contraction and relaxation of muscles using a machine or device to allow for possible resistance to change.

Doing a wall sit for 10 minutes is

Running fast up and down bleachers is

Riding a mountain bike up and down hills at a slow speed is