My swim interval times seem to always be off by a few seconds in Intervals.icu for some reason. I will show an example of a recent swim session of a 12x100m set:
This being the intervals.icu times
and this being the correspondent in Garmin connect
To help read the 2 images, so the first 100m interval reads 89s in intervals.icu and the that one corresponds to interval 3 in the garmin activity which reads 1:28.3 (88.3s). More evident on the following one that has 92s on intervals icu and 1:29.5 (89.5s) in garmin connect.
Hope it makes sense and was hoping to get some clarification why this might happen 
funny enough the average pace in the end is equal between garmin connect and intervals.icu. just the lap data appears with a couple seconds extra in intervals
Thanks!
I think it has to do with moving time. Garmin seems to remove the time from when you stop moving and when it ends the lap/interval. I can often go to the interval edit in intervals.icu and set the end time back by a second or sometimes two without changing the total distance. So it is likely logged into the lap (which is why intervals.icu counts it as such) but connect is putting it into the rest portion.
(I don’t know if you are using auto-rest, or using pre-programmed sets, so it may be different from what I see)
I personally dont mind too much the lap times being a bit off in intervals.icu, altho it makes me doubt if im hitting those times or garmin is being a bit optimistic and its intervals that is correct. To clarify I dont use auto rest, I manually start and stop the lap. I do use pre programmed sets but im manually clicking lap everytime I start and stop. Next time I guess I will compare it to the pool clock to make sure garmin is not eating away time thanks!
