One of AMP's main features is the ability to easily share content with different groups and members of your organization. If you have content mostly related to one athlete, you can upload that file directly to the athlete's profile. First navigate to the athlete's profile page. Once there, select Documents from the horizontal menu bar. 

Next, look on the right of the page for the "Share Instantly" column. You can drag and drop files onto that area, or browse your computer and select files. Notice that you can upload more than one file at a time:

If you select a file by mistake, hit the red x in the upper right corner of the grey box to deselect the file. If you want to remove all of your files at once, select "Clear Queue." 

Once you are happy with the files you have selected, click "Upload Files." 

By default when you Share Instantly, only the athlete whose profile you're on and his or her coaches will see the files you uploaded. If you want to share with a wider audience, you should select the blue "Change sharing permissions" words.

Read more about sharing permissions