When running with iWatch, you can take the following measures to prevent sweat from affecting the use of the watch:

1. Take a paper towel or towel with you and wipe the sweat off the watch surface in time.

2. Use sweat-proof tape or silicone strap to prevent sweat from penetrating into the watch.

3. If possible, you can fix the watch on the strap before running, and then fix the watch on your wrist when running.

Taking the above measures can effectively prevent the influence of sweat on the watch and prolong the service life of the watch.