Originally Posted by
mrtuttle04
The overall lower gearing on the 7.4 is better gearing for your situation. The 7.4 has smaller gears on the crank which is better for climbing while the 7.5 has larger gears on the crank which is better for top-end speed. Also the lower gearing will result in faster peddeling which means better cardio workout. The higher gears would be for building leg strenght.
The compact crankset will also give you an aerobic workout. The triple crankset will also give you leg strength.