First, I know that helmet looks too small. At least several people have told me that upon seeing this photo. It's not, though. So there.
I live near Lake Nokomis, which is part of several nearby lakes that are surrounded by bike paths. However, if you really want to get your heart rate up, the lake paths are not the best. They have a posted 10 mph speed limit, which is not enforced, but it's still a good idea. Between slower riders, pedestrians and roller bladers, it's just too crowded to keep a constant speed.
However, you can hit the sidewalk that parallels the lake on the east and north sides and really pick up some speed without the traffic of main street.
The photo below is the trail on the north side of Lake Nokomis. You should see these trees in the spring. They are covered with white and pink blossoms.
I like to head toward Minnehaha Falls and then down into Ft.Snelling. To get there, you jump onto the Minnehaha Creek bike path. The photos below are of a bridge over the path I found along the way.
Below is the John H. Stevens House, which was a civic meeting place built in 1849.
Below is the back of Minnehaha Falls.
Below are the falls. They say the rocks below the falls are deteriorating and in need of repair. It may not look like this long. Photo take June 14, 2008.