I have made a small interval training program:
2 km startup
5 repetiutions of 5 repetitions of 30-20-10 sec intervals, but I cannot send it to my 310XT.
I have debugged by making a small training session with only two steps. Same issue - when interval is shorter than 1:00 (eg. 0:59) it does not upload.
Guess I have to revert to Garmin Training center to create this program.