I find that I get a very good workout, staying with no assist in flat areas, and mostly first, and occasional second or third levels in hillier or off-road areas. Consider that with any electric, you are pushing a significantly heavier bike; so, even on flat ground, sans assist, you are using at least twice as much effort as on a regular bike. Depending on your terrain, and other variables (including standard gearing), you can easily get an even tougher workout pushing a 50-pound-and-beyond machine.