To the OP, do you have any idea what cadence you feel comfortable with? I agree in theory with your boyfriend. A higher cadence, say around 90 rpm, is generally better from an endurance standpoint. I disagree, however, that you necessarily have to be in the little ring of a compact crank to achieve that. I can easily do so in my big ring. Now, you may have to build up to that, but in time, you should be able to comfortably use a wider number of your available gears.