I had a training at athletic stadium by size 400m, my training session: 8x (400m + 400m). the first 400m fast run (3:50/km and the second 400m slow run (6:00/km) garmin recorded a total run of 4330m. the error occurred during a fast run where the watch always shows approximately 320m and during a slow run it is a good 400m. I don't understand where could be a mistake.
