Bob,
Our methods were pretty primitive at the time. I suppose you could try to duplicate what I did in 1989 by using Gmap-pedometer, but that would be awfully laborious. Given current mapping tools, it shouldn't be necessary to interpret contour lines on old-fashioned topo maps.
MapMyRun has various idiosyncrasies. It produces a nice elevation profile, which appears to be fairy accurate, using its Full Screen map view. But I don't know any way to export the data from that profile. You CAN export the data when you're NOT in Full Screen mode by using its "Download Data" link, which produces a CSV file that you can import into a spreadsheet. The elevations obtained that way don't seem to be as accurate, but maybe they're good enough to estimate the steepness integral. One catch is that "Download Data" may provide only a sparse set of points along the course. To work around that problem, you need to generate the course using a dense set of points (maybe every 100 meters or so). Also, data points in the CSV file appear to be duplicated, so you'll need to account for that in your spreadsheet.
While the elevations obtained using MapMyRun's "Download Data" might be used for estimating the steepness integral, they aren't accurate enough for determining Start and Finish elevations (you might obtain those with Google Earth, unless extreme accuracy is needed, in which case USGS sources should be used).
Another note about MapMyRun. To obtain reasonably accurate distances, it's necessary to turn off its "Auto Follow Roads" feature and use a more manual approach to pick points along the SPR. I've included this tip in our website, see http://www.usatf.org/Products-...nal-Tools.aspx#gmaps