Hello sorry by my poor english.
I have erased an activity on garmin connect. I have it on forerunner 310t but I go to historial and sync again but activity not appears ¿its a way to send to garmin connect again?.
Yhanks
If the activity has loaded to your computer (and you can find it) you can upload it by using the "import" link on the Activities page (link is to the right of "+Manual Activity" so you may have to scroll the page sideways in order to see it)
This is the file path for a Mac and it will be something equivalent on a pc
Note that the "Library" folder is normally hidden - holding down Alt and clicking the "Go" menu in the finder allows you to open it (This is Mac again)