Team Bobs-Bicycles.com Training Aids
Author: Fritz Stafford
Published: March 26, 2015
A cycling computer with a heart rate monitor is an extremely valuable training aid. Inclusion of speed & cadence sensor as well as GPS location & elevation tracking is also very useful. Another nice feature is an atmospheric pressure sensor for more accurate elevation (and slope) tracking. Also, be sure the cycling computer supports multiple bikes, else you will need one for each bike, or reprogram the computer each time you ride a different bike.
The most common cycling computers seen at amateur XC MtB races are the various Garmin Edge models, especially the Garmin Edge 500. Everything mentioned in the preceding paragraph is available for ~$350, and Garmin is the patent leader in this field (e.g., ANT+ wireless communication protocol for heart rate sensor, speed & cadence sensor, and Garmin as well as 3rd party power sensors).
Garmin provides free “Training Center” software (that is fully accessible off-line) and “Garmin Connect” web site for logging your training session data. Garmin is also affiliated with Strava, so all Garmin devices are fully supported on Strava.
Cycling computers are available with monochrome or color displays, and touch-screen or push button (typically 4 buttons) user interfaces. Color displays are better for viewing map details, but this is a “marketing” feature, as viewing maps is not something that is done while riding. Monochrome displays have better visibility and draw less charge from the battery. Touch-screen user interface is a bad idea for a cycling computer, as the display can be changed inadvertently, and returning the display back to what you want requires a major diversion of attention, even stopping. Furthermore, sweat and rain / sprinkler droplets change the display. Finally, touch-screen user interface drains the battery much more quickly than push button interface.
Smart phones can also be used as cycling computers, as apps and heart rate monitors are available, and this is popular amongst the Personal Media set. However, these devices are even more susceptible to the touch-screen deficiencies described in the preceding paragraph, as the screens are bigger. Also, you will probably end up paying as much or more to outfit your smart phone to get a less compact and less capable solution.
Of course, the smart phone requires monthly service fee, cell phone signal and GPS signal to operate as a cycling computer. Whereas, the dedicated cycling computer does not require any of this, although GPS signal is required to track GPS location.
Cycling computers with heart rate monitors can be configured to display heart rate or pulse beats per minute, bpm, and this is an indirect indication of the body’s power generation. Note that heart rate is a lagging indicator of power generation, and not all of this power is being output to the bike.
There is code in the cycling computer and / or analysis software that converts the heart rate profile from timed activities into caloric energy generation over the duration of the activity. The algorithms for this are based on correlations between heart rate profile and power meters on a variety of cardiovascular training machines with built-in power meters (e.g., exercise bikes, rowing machines, Nordic skiing simulators). These algorithms rely on one key user input parameter, heart rate maximum (refer to the section “What is my heart rate maximum?” under the tab Training, Training Tips).
Power monitoring based on heart rate has various deficiencies, but it is reasonably consistent, and adequate for intermediate level XC MtB racers.
There are a variety of Power Sensors available that directly measure the power output to the bike. These power sensors are based on measuring elastic flex in various parts of the drive train, crank spider, or crank arm(s), or pedal(s), or rear hub, depending on the model. These Power Sensors cost ~$1000 – $2000, and they are not very portable between bikes.
Power monitoring based on Power Sensors provide real time feedback of power output, and this is very useful as both training tool (e.g., assure / track interval efforts, identification of over / under training) and racing tool (e.g., how much energy has been burned in a race is good indication of what remains available for the finish).
Power monitoring with Power Sensors, and with the data transmitted to the coaches / directors in real time, has become a must in the Pro Road Race Peloton. Power monitoring with Power Sensors is not as pervasive in XC MtB.