Power Testing with a Computrainer

posted Jan 3, 2011, 1:38 AM by Donald Vescio   [ updated Sep 12, 2011, 8:12 AM ]

There are a number of ways to establish baseline metrics that can be used to structure training sessions and to predict future performance.    The topic of training with performance data can be extremely complex; the purpose of this article is to outline specific ways in which a rider might be able to obtain data useful in assessing performance, structuring training, and predicting future performance.

Racermate’s Computrainer is an electronic load generator that is fixed to a rear wheel bicycle training stand.  The load generator is connected to a hand unit which may be used to control the load generator directly, and it also may be connected to a desktop/laptop computer, which offers more advanced opportunities for control.  What the load generator does is precisely adjust resistance to the bicycle’s rear wheel; this resistance is measured in wattage.  Users can leverage Computrainer’s precision to obtain accurate testing results useful for power and/or heart rate based training.  For more information on Computrainer, visit: http://www.racermateinc.com/


Testing for Anaerobic Threshold
An athlete’s anaerobic threshold is a reliable predictor for aerobic exercise (think: endurance).   In most endurance events, it is important to product a steady effort over an extended period of time.  In order to do this, the athlete wants to work at a high enough intensity to be competitive, while still being able to efficiently remove lactic acid as it is produced, thus preventing its buildup in the bloodstream.  Frequently, the term lactate threshold is used interchangeably with anaerobic threshold. 

Anaerobic thresholds will vary from person to person, and it also is dependent on fitness.  Untrained athletes may register an anaerobic threshold of less than 50% of their VO2 max (think: absolute maximum capacity to process oxygen during exercise), while highly trained athletes may see anaerobic thresholds approaching 90% of their VO2 max, depending on the specific sport.  The key point to remember is that athletes can improve their anaerobic thresholds through structured training, which means that they will, over time, be able to perform effectively in their events at increasingly higher levels of intensity.

Again, the anaerobic threshold should be regarded as the transition point when athletes shift from the use of long-term energy systems that support endurance efforts, to the use of short-term energy systems that provide significant amounts of power, albeit for short periods of time.  Aerobic efforts enable the efficient processing of lactic acid; anaerobic efforts deplete energy stores rapidly and exercise soon ends due to lactic acid build up.

In terms of training and racing, knowing your anaerobic threshold will enable you to effectively pace your efforts across events of widely varying durations.  Knowing your anaerobic threshold also helps you structure the intensity and duration of your interval workouts.


How to Test for Anaerobic Threshold
There are a number of ways to test for an athlete’s anaerobic threshold, but most center on the concept of monitoring one to two variables, such as heart rate and/or power, as work load increases steadily over time.   With the Computrainer, it is easy to provide a consistent work load increase by designing a hill of steadily rising gradient when used in 3D mode, or by progressively adding resistance when used in ergometer mode.    After the testing session is completed, heart rate and/or power data is plotted on an X/Y axis for analysis and interpretation.  As fitness improves, the athlete will notice a shift up and right on the X/Y graphs, which indicates an ability to perform at an increased level of intensity, without crossing over into lactic acid debt. 

For greatest utility, athletes should consider being tested on a regular basis to track progress toward specific fitness goals, as well as capturing data that will enable greater refinement of workout design.



Testing for Peak Power
Peak power efforts are anaerobic efforts, which by necessity last only a short period of time.  This value is good at tracking improvement in physical strength and the utilization of short-term energy systems. 

Peak power testing is a relatively simple proposition:  the athlete does an all-out sprint 20 and 40 seconds on a standard Computrainer course.  During the test, peak and average wattages are recorded.    Maximum watts for this effort provides a good indication of an athlete’s peak power output, while the average watts value has a strong correlation to an athlete’s power-endurance (which is vital for short-term, high intensity efforts).

Ideally, athletes should repeat this test every six to eight weeks to track progress in both peak power and power-endurance values.



Testing for Overall Fitness and Overtraining
In technical terms, a Ramp Test continuously raises an input system until the system breaks down.  In the context of triathlon and endurance sports training, a Ramp Test increases training load in an exponential fashion, while the variables of heart rate and perceive exertion are recorded over time.  This is most easily done in Computrainer’s ergometer mode, in which the athlete will ride at specific wattage levels for defined periods of time, normally no longer than three minutes at each stage.    As resistance levels increase, heart rate also will increase, though not in a linear fashion.  The goal of this test is not to cross over the athlete’s anaerobic threshold; rather, maximum effort should approach no more than 10 beats below the athlete’s anaerobic threshold.

A Ramp Test is a quick and easy way to assess the following variables:

·         Aerobic improvement

·         Identify potential overtraining or excessive fatigue

·         Assess recuperation

Additionally, Ramp Tests are an excellent tool to use as warm-up for intense interval workouts.

Athletes should consider completing Ramp Tests at least once per week.