What are some strategies to increase average power during races with a PowerTap G3 hub, considering the hubs data can sometimes be skewed by a riders position, wheel choice, and terrain, and how do these factors impact the effectiveness of traditional power-based training methods. Are there specific workouts or training programs that can be tailored to an individuals power profile as measured by the G3 hub, and what role do cadence and gear choice play in optimizing power output. How do experienced riders and coaches account for the nuances of the G3 hubs data, and are there any alternative metrics or tools that can provide a more complete picture of a riders performance.