Bike - Cadence

Cycling cadence is your pedalling speed.

It is measured in revolutions per minute (RPM).  This is the number of complete circles one leg completes in 60 seconds.

A smooth, fluid pedal stroke combined with a good cadence is an integral part of riding fast and efficiently.

Cadence varies:

  • between riders in the same conditions;
  • for the same rider in different conditions;
  • and for the same rider over different race distances and type.

There is no “one size fits all” perfect cadence, but in general a higher cadence (90+rpm) is optimal for triathlon.

Cadence ranges

The table below provides a definition of the cadence ranges used in this guidance note. 

Simplified Range

Cadence (rpm)

Detailed Range

Cadence (rpm)

Low

< 90

50-70

Very slow

70-80

Slow

80-90

Moderate

High

>= 90

90-100

Fast

100-110

Very Fast

110+

Extremely Fast

 On a flat surface at a given speed, if you ride with:

  • a low cadence using a harder gear, pedalling taxes your skeletal muscles, specifically your quads as you have to apply lots of force to turn the pedals.  Activities that repeatedly require a lot of force rely predominantly on fast twitch muscle fibres, these tend to burn glycogen as their primary fuel source;
  • a high cadence using an easy gear, pedalling is going to tax the cardiovascular and respiratory systems.  Because of the easy gear, it will produce less strain on your muscles.  Assuming that you have adequately developed the neuromuscular pathways to allow you to pedal comfortably at a higher cadence you will rely more on slow twitch muscle fibres and fat as your primary source of fuel.

 Understanding the load and fatigue generated in your muscle and your usage of fuel is important in triathlon because following the bike is a run.

The same principle applies in running that the higher the cadence (total number of foot strikes per 60s) the lower the muscular strain BUT at whatever run cadence you employ for a given effort there is significantly more muscular strain in running than cycling and therefore more muscle fatigue and reliance on glycogen as a fuel source.

When competing in a triathlon you need to ensure during the bike you optimise your effort (force vs. cadence) to limit the fatigue in your legs and the depletion of you glycogen stores so that you can run well off the bike.

Other advantages of a high cadence riding

A high cadence places less stress and torque on your knees.  If you have bad or weak knees, you’re usually better off spinning faster, in a low gear – remember during the run the knees are under a higher load.

Spinning fast in a low gear allows for faster accelerations, because you can quickly increase your cadence to increase your speed.  If you need to shift gears, that is also easier, since the drivetrain in under less stress.

Having the ability to ride at higher cadences is also important because when you cycle down a steep hill you may reach your top / hardest gear – the only way to go any faster is to increase your cadence.

Simplified Summary

Cadence

Rpm

Main load

Muscle type

Fuel source

Sustainable duration

Low

 

 <90rpm

Skeletal muscles (quads)

Fast twitch

Glycogen

Shorter

High

>=90rpm

CV and respiratory system

Slow twitch

Fat

Longer

Understanding cadence

In order to optimise your cadence it requires the collection of your cadence data in conjunction with your heart rate, speed, and if you have it power data, when riding in a variety of conditions and courses.  Applying the principle of specificity by practicing on the race course or a one very similar in terrain and profile will enable you to optimise your cadence throughout the entire ride.

Key Equipment for developing cadence

  • Cadence sensor – one that works with your GPS/HR device.
  • Turbo trainer

Cadence and/or Speed Sensor

There is usually a specific cadence sensor or a cadence & speed sensor made by the manufacturer of your GPS/HR device that is guaranteed to work – sometimes when you purchase a GPS device you can get a bundle offer that includes HR monitor and cadence (& speed) sensor.

Although a speed sensor is not required for developing cadence it is recommended to have one because:

  • If you lose GPS signal outside you can still record distance
  • In the absence of a power meter it is possible to use speed as proxy for power and perform coupling tests on a turbo trainer
  • Having both a cadence and speed sensor will allow you to utilise online training tools such as Trainer Road.

Most devices utilise one of two communication protocols: Ant+ or Bluetooth Smart.  Some newer devices support both protocols and there are some devices that use their own specific protocol.  As long as you purchase a sensor with the same protocol as your device it should work i.e. you are not limited to the sensor manufactured by your GPS device manufacturer.

Both Ant+ and Bluetooth Smart have their own websites which list devices that use their protocol.  At the time of writing Ant+ devices have the widest range of devices and sensors.

Ant+ devices – http://www.thisisant.com/directory/

Bluetooth Smart – http://www.bluetooth.com/Pages/Bluetooth-Smart-Devices-List.aspx

Garmin

Garmin devices are Ant+.  The sensor options from Garmin are:

Turbo Trainer

Terrain, profile and weather conditions can significantly impact your cadence so eliminating these by using a turbo trainer will allow you achieve a specific cadence and intensity level.

If you do not have a turbo trainer then there are a wide range of options.  For an excellent overview of the options visit the DC Rainmaker website: