FitnessExplorer exercise graphs display not only the exercise fields versus time but also simultaneously shows the spectral histograms of the fields. Highligh part of the graph and the spectral histograms are dynamically updated in real time. Zoom in to a small part of the graph and play with the scroll bar to fly the graph backward and forward.
Displaying multiple exercise graphs simultaneously is a powerful tool to compare performance over time.
FitnessExplorer supports any number of ranges. They can even overlap. Here is a graph with 4 saved ranges. (The one on the bottom of the graph shows the range used for the statistics and histograms.) Clicking on a saved range makes it the current ranges and updates the statistics and histogram.