One thing that would be a great help in analyzing training data would be to incorporate weather data automatically. Temperature, cloud cover, precipitation, humidity affect the workouts as much as elevation, and should be easy to obtain automatically on one of the dozens of internet weather sources, maybe using time and coordinates to find the nearest weather station. This would definitely make a great edition for Garmin Connect!
EDIT: I see that this has been addressed plenty of times in this topic, most recently February, so here's a "bump" hoping they're working on it! Just did intervals on a 100-degree day, so it's fresh on my mind!
