For what it's worth, vigorous exercise is barely more than walking: http://www.cdc.gov/physicalactivity/basics/measuring/heartrate.htm http://www.cdc.gov/physi

For what it's worth, vigorous exercise is barely more than walking: http://www.cdc.gov/physicalactivity/basics/measuring/heartrate.htm http://www.cdc.gov/physicalactivity/basics/measuring/heartra... E.g. if you do an hour on the elliptical machine at 150 bpm then that's already 80% of your exercise RDI for the week.