Is there an optimal Cadence for cycling performance? The results from Cadence research is all over the place, there are studies finding high cadence is beneficial, while others advocate for low cadence and some saying that self-selected cadence is most economical. And throughout these, there are many who are super happy spinning at 110 and many who ride happily day after day doing 60 rpm.
It's generally understood the oxygen uptake, heart rate, stroke volume, cardiac output, and blood pressure increase with increased cadence, while vascular resistance decreases at the same time. Which is why pros usually prefer higher cadence, as their cardio vascular fitness is as high as it could be for each of them. Alas, even pros change their cadence based on the terrain that they are riding i.e., lower cadence while climbing and high cadence in the flats. At same time, research shows that higher power output leads to higher cadence. While optimal cadence may not differ between experienced and inexperienced cyclists at low power outputs, optimal cadence moves rightwards with increasing power to the point where experienced cyclists may exhibit higher cadences simply because inexperienced cyclists are not able to operate. Simply put, riding at the higher output causes one to ride at higher cadence, not the other way around. Thus, the hypothesis that you need to spin to ride fast is simply *Not True*.
As for slow twitch and fast twitch muscle composition and their role in cadence selection, it's been shown as contraction velocity increases above ~67 rpm, slow twitch fibres become inefficient as they move beyond their optimal contraction rate; while fast twitch fibres become increasingly efficient at cadences about 110 rpm.
In addition, there is research that concludes cadence did not have a dramatic effect on efficiency regardless of cycling experience or fitness level across 50 rpm to 110 rpm with self-select cadence included as well.
There is no single optimal cadence for all cyclists nor a single optimal cadence for an individual. Indeed the cadence at which perceived exertion is minimized strikes the optimal trade-off between metabolically efficient cadence and mechanically efficient cadence. And even this cadence will change based on many factors such as work-load, training adaptations, environment, and terrain.
As for training, low cadence training has been shown to improve power output mostly due to increase in testosterone and neuromascular adaptation as opposed to high cadence training. However, when compared to just regular self-selected cadence training, the low cadence training seems to be inferior.