The present invention relates generally to exercise equipment and more specifically, to an isometric exercise apparatus and a storage rack therefor. The isometric exercise apparatus includes a frame which has a base and a sidewall joined to the base. The base has an exercise platform for supporting a user's body. Also provided is a restraint arm assembly connected to the frame. The arm restraint assembly includes a swing arm pivotally connected to the base, a restraint arm carried by the swing arm and positionable above the exercise platform to inhibit movement of a portion of the user's body so as to allow the user to perform isometric exercises. An indexing assembly is provided to fix the swing arm in a predetermined angular position selected from a set of discrete angular positions relative to the base. At least one limb restraint accessory is positionable at predetermined locations along the base for inhibiting movement of the user's limb so as to allow the user to perform isometric exercises. The apparatus can rapidly be adapted or configured to target a plurality of joint angles to work different muscle groups (or different muscles within the same muscle group) for an enhanced isometric workout.