Optimal Cadence

What is the optimal cadence for cycling performance in a race? What about inducing adaptations during training? Furthermore, is there scientific merit to low cadence training that we see the pros do?

First of all, variation in cadence affects muscle fibre recruitment, which adapts to different force and velocity demands. The figure below illustrates changes in blood lactate levels at a constant power output of 300 watts, revealing significant shifts in muscle fibre activation across different cadences.

Lower cadences minimise energy demand and oxygen utilisation. The chart below shows curves of oxygen uptake vs the cadence at a given power output of 5 trained cyclists. We can see that the dots are the minimum, and they occur at relatively low cadences. Also notice that at lower power outputs, lower cadences are the most efficient.

Even though energy expenditure and oxygen usage are minimised at lower cadences, cadences that are slightly higher mitigate muscular fatigue [2]. The figure below shows the amplitude of electrical signals in 10 trained triathletes legs, which is a proxy for the rate the muscles will fatigue. Observe that minimum values occurred at higher cadence ranges than the previous chart.

Our perception balances metabolism (oxygen usage and energy expenditure) and muscular fatigue to determine our optimal cadence. The authors found that cyclists subconsciously do this. See that the minimal rate of perceived exertion (RPE) occurs approximately at the crossover point of oxygen uptake and torque.

Lastly, at high powers, your metabolic expenditure is less sensitive to different cadences. In the figure below, you can see that increasing the cadence resulted in less of a relative increase in oxygen usage at 300 watts compared to 100 watts.

In short, self-selecting your cadence based on what feels easiest is the most scientifically-backed approach for peak performance.

Regarding low cadence training, Jay Vine discusses in a YouTube video how his coach prescribed a set of 4 minutes at 400 watts with a cadence of 50rpm. By comparing the forces during this exercise to squatting, we find that pedaling generates approximately 450 Newtons. In contrast, assuming a body weight of 70kg and squatting 90kg, the force experienced would be about 1570 Newtons [4].

This is a rough approximation, but it's clear that holding a pace for 4 minutes is less demanding than squatting, leading to different adaptations. In terms of strength training dogma, comparing 5-6 reps to 4 minutes is impractical; the latter targets endurance. To illustrate this see the figure below, which is the National Association of Strength and Conditioning’s continuum of rep-ranges and adaptations. [5].

In summary, low cadence work cannot replace strength training for inducing muscular adaptations. However, adding torque training to an existing strength program could be beneficial, although there is no published scientific evidence supporting this.

Notes

[1] Unless otherwise cited, the information in this article comes from this review from the European Journal of Sports Science. All figures are screenshots taken from the article, and have been produced by Les Ansley and Patrick Cangley.

[2] “​​Elevated root mean squared (RMS) or integrated electromyogram (iEMG) amplitude in trials indicate increased muscle activation due to an increase in the number of motor units recruited and/or an increased contribution from FT motor units (where the larger fibre cross-sectional area generates increased action potential voltages). An increased firing rate to meet additional force demands is also reflected in an elevated iEMG.” - Excerpt from the review in the first note.

However, the authors note that EMGs are tricky to perform, so some studies report linear relationships, or no changes. However, other studies corroborate increase in neuromuscular strain at lower cadences and the visualisation is nice.

Furthermore, we acknowledge the comparison between the minima of the VO2 chart and the EMS chart is not the best since it uses averages based on different athlete groups. However, the authors provide more evidence to support that athletes self-select cadence based on RPE minimisation, which is based on both muscular fatigue and metabolic efficiency, so it’s a good way to make the argument.

[3] Jay Vine explains his torque training in this video.

[4] Torque = Power / Angular Velocity; Torque = 400 / (50/60 * 2π); Torque = 76.4 Nm

Force calculation assumes that Jay Vine has 172.5mm cranks, squats 90kg, and weighs 70kg.

Force on both pedals combined assuming constant torque: Force = torque / length; Force = 76.4/0.1725; Force = 443 N

Force on both of Jay’s legs assuming all of Jay’s weight contributes: Force = mass * gravitational acceleration; Force = 160 * 9.81; Force = 1570 N

[5] From the Basics of Strength and Conditioning Manual by the National Association of Strength and Conditioning. Graph is from page 17.