I say you should train pretty hard, just train train.
A rider can only shift as much as his bike allows. The traditional two chainring setup, with a 12-23 tooth cassette, is insufficient for all but the flattest terrain. Once the rider reaches a moderate climb, his cadence will drop below 80 rpm even with a hard effort in his lightest gear.
A wider range of gearing on a cassette (12-25 or 12-27) can remedy that by giving him an easier "bail out" gear, but results in big gaps between gears. A third chainring is another option, though he will pay a penalty in weight and in sluggish, finicky shifting. A less common but increasingly popular alternative is the compact crank. It uses two chainrings, but with fewer teeth per ring (50 and 34 or 36 as opposed to 53 and 39), resulting in lighter gear ratios for higher cadence climbing.
If you have trouble maintaining speed at high cadences, don't give up and assume you're doomed to a life of low rpm's and dead legs. In training, gradually increase your cadence comfort zone by doing high-cadence accelerations on a slight descent. Choose an unusually light gear and spin as fast as possible for 15 to 20 seconds without your hips bouncing in the saddle. Recover for a minute and repeat five to seven more times.
A popular method among roadies is to ride a fixed-gear bike on rolling terrain using a gear that's appropriate for the climbs and therefore too light for the downhill sections. This forces you to ride at a higher cadence, and promotes greater neuromuscular efficiency.
Remember: The prize goes to the first racer across the line, not the one with the most macho gear selection. Prudent, ego-free gearing can help get you through your ride quickly and efficiently.