Haptic feedback

1. An exercise accessory, comprising:

a handle;

a haptic actuator included in the handle, wherein in response to an indication of an event pertaining to a load on the handle, the haptic actuator is configured to generate a vibration pattern corresponding to the event; and

a memory configured to store a mapping of events to corresponding vibration patterns, wherein different events are associated with different vibration patterns;

wherein an update to the mapping of events to corresponding vibration patterns is transmitted to the exercise accessory wirelessly from an exercise machine with which the exercise accessory is coupled.

2. The exercise accessory of claim 1 , wherein the event comprises a command to turn on or off a digital weight.

3. The exercise accessory of claim 1 , wherein the event comprises adjustment of weight loaded by the exercise machine with which the exercise accessory is coupled.

4. The exercise accessory of claim 1 , wherein the vibration pattern corresponds to an amount of weight loaded by the exercise machine with which the exercise accessory is coupled.

5. The exercise accessory of claim 1 , wherein the event comprises counting down to an end of a movement set.

6. The exercise accessory of claim 1 , wherein the event comprises detection of incorrect form.

7. The exercise accessory of claim 1 , wherein the event comprises detection that a user performing an exercise is struggling.

8. The exercise accessory of claim 1 , wherein the vibration pattern is generated according to a vibration command, wherein the vibration command comprises a vibration intensity and one or more vibration duration pairs, and wherein a vibration duration pair comprises a silent period and a vibration period.