Originally Posted by
puddinlegs
In the end, the only way to get faster climbing is to climb. Weight loss is easier with a clear performance goal.
Provided you don't run out of gears, power gained riding intervals on flat ground or a trainer works going up-hill too. Riding on flat terrain is better for hill climbing than going up mountains when flat weekday rides start at your front door without driving to hills cutting into your riding or sleeping time.
Some people have motivation issues riding hard on flat ground, although that's a psychological problem not a physiological one.
Some people loose power with moderately low cadences, like the racer in Training and Racing with a Power Meter who got dropped every time he spent more than five minutes at his one hour power but with a cadence below 70 RPM. Gears can fix that.