So why would a bike fit be the most economical way of improving your experience & performance on two wheels? Actually, there are several reasons:
1. optimized aero position. The number one resistance we face when cycling is of the aerodynamic variety. Upwards of 75% of the total resistance we encounter comes in the form of the human body, the rest coming from the combination of bike & rolling resistance (Serious Cycling, Burke, 2002). Thus, if a person reduces his or her frontal drag area they will have less wind pushing against them, helping them to move faster. Simple.
2. maximize power. You want - need - your legs to work in unison to produce the most powerful, efficient pedal stroke. If your saddle height is too high or low it will cause undue fatigue & wasted energy. A muscle cannot produce maximum force at its end range of motion. This limits the effectiveness of the most important muscles that are propelling you forward; your quads, hamstrings and glutes. Having a bike fitter who understands the human body is imperative.
3. comfort. This is the most important one, and often the most overlooked. The tendency from many bike fitters is to put the athlete in the most aerodynamic position possible and send them on their way. But have you ever been to watch, or participate in an Ironman race? It's amazing how many athletes are riding $10,000 bikes but can't stay down in their aerobars for more than 20' at a time. And those $4000 set of deep dish Zipp wheels? Wasted if you have to sit up to stretch your back every few kilometers.
position+power+comfort=YOUR BEST RIDE!