You could try a new datafield I have just uploaded to the connect store. I made it primarily for interval training so you configure it with warmup distance, interval distance, recovery distance, number of reps and target pace for the interval. During warmup and recovery it counts down the meters left, during the interval it shows how far behind or ahead you are in seconds and provides audio and tactile (vibration) feedback. If you get more than about 0.5 second behind it beeps and gives three short bursts of vibration to urge you to speed up, if you are more than 2 seconds ahead it beeps and gives one long burst of vibration to tell you to slow down. This means you can pace yourself very accurately without having to look at your watch.
For a single run/race, you can configure the warmup as 0, interval set to race distance, recovery set to 1000 or so (so it has something to work on), reps to 1 and pace to your target pace.
For interval training I normally also configure a workout through Garmin Connect to match the distances in the interval pacer. That way I get the appropriate laps in my results.
Please note that for the time being this datafield is strictly metric, so inputs are all in meters and pace is in minutes per km.
If you do use it please let me know how you get on.
